Opinion by
JUDGE DUNN
{1 No doubt Colorado is a state blessed with natural beauty. Seeking, in their view, to highlight this beauty, several years ago artists Christo and Jeanne-Claude began a quest to install a large-scale art display over the Arkansas River (the Project). Over a decade after the initial application, the Colorado Division of Parks and Outdoor Reere-ation (Parks Division), through its Board,1 authorized the Project.
T2 Rags Over.the Arkansas River, Inc. (ROAR), a nonprofit organization, seeks judicial review of the Parks Division's authorization of the Project, contending that the approval was arbitrary and capricious. Namely, ROAR alleges that the Parks Division: (1) failed to follow its regulations for issuing special activities permits and (2) unreasonably approved the Project contingent upon (a) authorization of the Project by the Bureau of Land Management (Bureau) and (b) implementation of mitigation requirements to be included in a not-yet-final federal Environmental Impact Statement.
138 We agree that the Parks Division's failure to adhere to its own special activities permit regulation in approving the Project was arbitrary. | Because ROAR is unable to demonstrate prejudice as a result of the procedure by which the Project was approved, however, we nonetheless affirm the Parks Division's approval of the Project.
I. Factual Background
T4 The Arkansas Headwaters Recreation Area (AHRA) consists of a 148-mile stretch of river and surrounding land designated for outdoor pursuits including rafting, fishing, | camping, and sightseeing. The AHRA is primarily managed by the Parks Division, but a majority of the land is federally owned and is thus under the Bureau's partial jurisdiction.
T5 In 1996, Christo and Jeanne-Claude first approached the Parks Division to discuss their vision to suspend translucent fab-rie panels over approximately six miles of the Arkansas River. The fabric panels would roughly follow the changing width and course of the river and would be broken into several sections along the river's corridor. In the artists' view, the effect of the light passing through the overhead fabric would enhance the beauty of the river and its surroundings.
T6 The artists formed Over the River Corporation (OTR), an intervenor in this action, to facilitate the Project. In accordance with the Parks Division's regulations, OTR applied for a special activities permit for the Project in 1997.
{7 From 1997 until 2001, the Parks Division and the Board, in collaboration with other federal, state, and local agencies, began analyzing the possible impacts of the Project. Environmental, economic, safety, infrastructure, and wildlife impacts were the paramount concerns. ‘
T8 For a variety of reasons, the Project was largely dormant between 2001 and 2006. In 2007, the Parks Division and the Board entered into a formal agreement with the Bureau and other state and local agencies to coordinate further evaluation of the Project and to assist in the preparation of a federal Environmental Impact Statement. The formal agreement stated that the Parks Divi[189]*189sion would coordinate with other.state agen-cles to ensure that all agencies were aware of the necessary mitigation requirements identified in the final Environmental Impact Statement before authorizing the Project.
T9 Unrelated to the Project, the Parks Division and the Colorado Wildlife Commission were slated to merge in the summer of 2011. In May, shortly before the merger, the Wildlife Commission notified the Parks Division, the Bureau, and other participating agencies that it opposed the Project because of its impact on certain wildlife populations, including bighorn sheep and golden eagles.
110 Several days after the Wildlife Commission voiced its opposition, OTR sought a decision from the Parks Division on the Project. To that end, OTR presented a draft cooperative agreement for the Board's consideration. Although the Board had previously announced its intent to wait for the final Environmental Impact Statement to be issued before authorizing the Project, the Board decided to move forward with assessment of the Project. The Board also began negotiating approval of the Project through the cooperative agreement proposed by OTR, rather than issuing a special activities permit under its regulations.
{11 A week before the Parks Division merged with the Wildlife Commission, the Board voted to authorize the Project through a memorandum of agreement (the Agreement) with OTR. The Agreement authorized OTR to install, exhibit, and remove the Project subject to a number of conditions. OTR agreed to, among other things, provide the Parks Division with a detailed Project schedule, pay a recreation impact fee, and implement mitigation measures after the Project's completion.
12 Final approval, however, was expressly conditioned upon the Bureau's authorization of the Project and compliance with "measures developed by the [Bureau] which are intended to mitigate the adverse environmental impacts of the OTR Project, require the implementation of the mitigation measures by OTR 'and provide for monitoring and enforcement of these mitigation measures."
113 ROAR sued the Parks Division in district court, seeking judicial review of the Project's approval. Among other relief requested, ROAR sought to enjoin the Project. In a written order entered on the pleadings, the district court concluded that the Board's approval of the Project through the Agreement was not arbitrary and capricious. As well, the court concluded that the agency's decision to approve the Project, reached after considering the impacts to the AHRA, was supported by sufficient record evidence. Accordingly, the court affirmed the Board's decision and dismissed ROAR's complaint.
IL -Standard of Review
T 14 Our review of agency action is highly deferential. Coffman v. Colo. Common Cause, 102 P.3d 999, 1005 (Colo.2004). We must affirm an agency's decision unless we find that it is, among other things, arbitrary and capricious; in excess of statutory jurisdiction, authority, purposes, or limitations; an abuse of discretion; based upon erroneous findings of fact; or unsupported by substantial evidence, § 24-4-106(7), C.R.S. 2014; Well Augmentation Subdistrict of Cent. Colo. Water Conservancy Dist. v. City of Aurora, 221 P.3d 399, 417-18 (Colo.2009).
IIL The Parks Division's Review and Approval of the Project
115 The General Assembly delegated the authority to develop regulations for management of the state parks and recreation areas and development of outdoor recreation programs to the Parks Board. See §§ 88-10-106, -107, C.R.S. 2014.2
T16 Consistent with this statutory guidance, the Board issued regulations to manage the use of state parks and recreation areas. See Dep't of Natural Res., 2 Code Colo. Regs. 405-1:100 to -8:807. The regulations outline procedures for allowing members of the public to obtain a permit to conduct. a special activity on areas under the Parks [190]*190Division's jurisdiction: See 2 Code Colo. Regs. 405-1:100, 1:101, 7:708.
€17 The regulation broadly defines "special activities" as "those events which have the potential for a significant adverse impact on park values or the. health, safety or welfare of park visitors or which may otherwise require special planning/scheduling for proper management." 2 Code Colo. Regs. 405-l:101(a) And the regulation states that "Islpecial activities shall require prior approval in the form of a Special-Activities Permit." Id.
¶ 18 A person or entity seeking a permit must apply at least ninety days prior to the proposed event and pay a filing fee. 2 Code Colo. Regs. 405-7:708(1). The decision to approve special activities permits is made by the park manager or, in some cases, the regional manager. Id. at 405-7:708(2). Whether -a permit is issued depends on several factors, such as the nature of the particular park, the size of the activity, the burden on park staff, and the impact on the park. Id. A. permit will not be granted if the special activity would have a significant adverse impact on park values or the relevant area management plan. Id. at 405-7:703(8).
A. Pursuit of Project Approval Under the Special Activities Regulation
19 In accordance with these regulations, OTR applied for a-special activities permit for the Project in 1997. Because of the scale of the Project, the Parks Division formed a multi-agency permit planning team to analyze the application.
20 For roughly thirteen years, OTR, the Parks Division, and the Board treated the Project as a special activity and proceeded under the special activities permit regulation:
® At a 1997 public outreach meeting, members of the permit team thanked. the public for "participating in the process of determining if a permit should be granted or denied to Christo and Jean[ne]-Claude."
~* A 1997 analysis of the Project noted that a "Colorado State Parks Special Event Permit" was needed. ©
eIn 1998, the Board wrote that, per the regulations, the "ultimate decision in approving the Project" may "rest with the > Regional Manager" per the special activities regulations.3
eIn 2000, an information bulletin about the Project indicated that the Parks Division would issue a "special event permit."
e A 2001 Board meeting agenda also stated that that the Parks Division would issue a special event permit for the Project.
e In 2006, the Board reaffirmed that approval of the Project would be through a "Colorado State Parks Special Activity Agreement." 4
e In 2009, another Board meeting agenda noted that, "the Parks Board will ... consider issuing a Colorado State Parks Special Activity Agreement" for the Project. |
T21 In September 2010, however, some confusion arose regarding the form that the permit would take. For example, in a PowerPoint presentation made to the Board that month, a slide stated the permit "would not look like a special activities permit.5 Yet, another slide in the same presentation suggested that the Parks Division would issue a special activities permits And during the meeting, a Board representative stated, "State Parks will have the special use permitting part of [the Project]." 'Later in that meeting, however, the same representative indicated that the permit would not look exactly like a special activities permit,. Despite some inconsistent statements regarding the form of the permit, the administrative record reflects no real dispute either that the Project was a special activity. under the regulation or that a permit was required.
[191]*191B. Project Authorization Through the Agreement
122 After the Wildlife Commission expressed its disapproval of the Project but before the merger with the Parks Division, OTR's counsel requested that the Parks Division "work toward an agreement fairly soon." Counsel for OTR then submitted a proposed "memorandum of agreement" to the Board that purported to authorize the Project: At the May 2011 Board meeting, the Board, with little explanation, abandoned the special activities permitting process. Instead, the Board switched course and approved negotiation of a coopergtivé agreement with OTR.
123 The June 2011 Board meeting was dedicated almost entirely to the Project,. A Board representative tasked with responsibility for analyzing the Project spoke about the draft agreement. Throughout his presentation, the representative did not mention issuing a special activities permit,. He did, however, rely on other parts of the special activities regulation. For example, in advocating for greater monetary compensation for the Parks Division, he said, "under our regulations, Section 703, I believe ... [a] special use activity fee" may be collected. And, even the Agreement itself references portions of the special activities regulation, including a clause waiving parking fees generally charged for special activities Notwithstanding the Board's selective reliance on portions of the special activities regulation, and the regulatory requirement that a permit "shall" be required for any special activities, the Board concluded that the Agreement was the "appropriate way" to handle the Project.
124 The only contemporaneous explanation for the Board's change in course came in response to a public comment that the Board was not following its permitting regulations. Answering this concern, a representative agreed that the Project "could have been handled as a special activities permit under the regulation." However, the representative stated that approving the Project through the Agreement allowed the Board, rather than the regional manager, to be "involved in the actual decision." At the close of the June 2011 meeting, the Board voted to approve the Agreement.
IV, Interpretation of Ageney Regulations
25 Upon enacting regulations, an agency is bound by them. Service v. Dulles, 354 U.S. 363, 388, 77 S.Ct. 1152, 1 L.Ed.2d 1403 (1957); accord Cherokee Nation of Okla. v. Norton, 389 F.3d 1074, 1078 (10th Cir.2004); see also Nat'l Envtl. Dev. Ass'n's Clean Air Project v. Envtl. Protection Agency, 752 F.3d 999, 1011 (D.C.Cir,2014) ("[An] ageney is not free to ignore or violate its regulations while they remain in effect." (internal quotation marks omitted)). It is.in fact "axiomatic that an agency must adhere to its own regulations." Brock v. Cathedral Bluffs Shale Oil Co., 796 F.2d 533, 536 (D.C.Cir.1986). . This ensures reliability and fairness. Sierra Club v. Van Antwerp, 526 F.3d ,1353, 1368 (11th Cir.2008) (Kravitch, J., concurring in part and dissenting in part).
¶ 26 Indeed, requiring an agency to follow its own regulations comports with principles of due process; that is, the public is entitled to know the manner in which an agency will render a decision and the factors the agency will consider, See Lobato v. Indus. Claim Appeals Office, 105 P.3d 220, 228 (due process principles require agencies to put individuals on notice of the agency's procedures); accord Montille v. Immigration & Naturalization Serv., 926 F.2d 162, 164 (2d Cir.1991) (the "notion of fair play" precludes an agency from having promulgated a regulation affecting individual interests and then ignoring or disregarding the regulation in its discretion). In light of these principles, "[the failure of an agency to comply with its own regulations constitutes arbitrary and capricious conduct." Simmons v. Block, 782 F.2d 1545, 1550 (11th Cir.1986). An agency must serupulonsly follow the reg- - ulations and procedures it promulgates and, if it does not, the court may strike the agency's action. See id.; see also United States ex rel. Accardi v. Shaughnessy, 347 U.S. 260, 266-67, 74 S.Ct. 499, 98 L.Ed. 681 (1954); Exportal LTDA v. United States, 902 F.2d 45, 46 (D.C.Cir.1990) (reversing agency action that was "flatly inconsistent with the plain terms" of the agency's regulations); [192]*192Am. Fed'n of Gov't Emps. AFL-CIO, Local 3090 v. Fed. Labor Relations Auth., 777 F.2d 751, 758 (D.C.Cir.1985) (agency action that is inconsistent with its existing regulations cannot be sustained by the court).
T27 Thus, while an agency's reasonable interpretation of its own regulations is ordinarily entitled to deference, Chase v. Colo. Oil & Gas Conservation Comm'n, 2012 COA 94, ¶ 20, 284 P.3d 161, an interpretation that is inconsistent with the plain language of the regulation is not. Udall v. Tallman, 380 U.S. 1, 16-17, 85 S.Ct. 792, 18 L.Ed.2d 616 (1965); accord Thomas Jefferson Univ. v. Shalala, 512 U.S. 504, 512, 114 S.Ct. 2381, 129 L.Ed.2d 405 (1994); see also Exportal, 902 F.2d at 50 (where agency regulation is unambiguous, the court does not defer to agency's interpretation). Nor do we defer to an agency's interpretation that is inconsistent with its own rules or policy. Williams v. Kunau, 147 P.3d 33, 36 (Colo.2006); see Tebbetts v. Whitson, 956 P.2d 639, 641 (Colo.App.1997) ("[Nlo deference is given when the agency's interpretation is inconsistent with its own rules."). It follows that we may reject an agency's interpretation of its regulations if the language of the regulation compels a different meaning. Exportal, 902 F.2d at 50-51; see also Chase, ¶ 23. Indeed, where a regulation plainly requires a different interpretation, "[t]o defer to the agency's position would be to permit the agency, under the guise of interpreting a regulation, to create de facto a new regulation.". Christensen v. Harris Cnty., 529 U.S. 576, 588, 120 S.Ct. 1655, 146 L.Ed.2d 621 (2000).
28 We construe agency regulations as we do a statutory provision; we look first to -the regulation's plain language. Gessler v. Colo. Common Cause, 2014 CO 44, ¶ 12, 327 P.3d 232; Chase, 122. If the plain language is unambiguous, we need not resort to other canons of construction. See Vigil v. Franklin, 103 P.3d 322, 327 (Colo.2004). All words not otherwise defined in the administrative regulation should be attributed their ordinary and customary meanings. Gessier, ¶ 22; Williams v. Colo. Dep't of Corr,, 926 P.2d 110, 112 (Colo.App.1996).
V. The Parks Division's Failure to Follow its Regulation
129 ROAR asserts that the Board was required to follow its special activities permit regulation, and the failure to do so was arbitrary and capricious, The Parks Division counters that because the special activities permit regulation was not designed to accommodate an event of the Project's size and duration, a special activities permit was not required.
130 The Parks Division does not dispute that the Project is a special activity within the regulation's definition.6 Nor does it dispute that, for at least thirteen years, the Project was treated as a special activity requiring a permit. Rather, the Parks Division argues that the special activities permit is not the exelusive means by which the Project could be approved; thus, it could depart from the regulation at its discretion. Because the plain language of the regulation dictates otherwise, we disagree.
131 The special activities regulation states that "special activities shall require prior approval in the form of a Special-Activities Permit." 2 Code Colo. Regs. 405-1:101(a). This language is categorical, and unambiguously prescribes a mandatory procedure. See Nat'l Ass'n of Home Builders v. Defenders of Wildlife, 551 U.S. 644, 661, 127 S.Ct. 2518, 168 L.Ed.2d 467 (2007); accord Associated Gov'ts of Nw. Colo. v. Colo. Pub. Util. Comm'n, 2012 CO 28, ¶ 48, 275 P.3d 646 ("The word 'shall is mandatory."). It thus imposes "discretionless obligstions" on the agency. Home Builders, 551 U.S. at 661, 127 S.Ct. 2518 (internal quotation marks omitted); see also Exportal, 902 F.2d at 50-51 (agency had no discretion to deny a bond waiver where the regulation stated the bond "shall be waived").
132 Had the Parks Division intended to make the special activities permitting regula[193]*193tion discretionary, it could have drafted the regulation to accomplish that goal. That is, the regulation could have simply preserved the Parks Division's discretion to waive the permit requirement, Or it could have expressly provided methods for excluding an event from the permitting regulation based on the event's size, scope, duration, or other consideration. Yet it did not. See Watson v. Pub. Serv. Co. of Colo., 207 P.3d 860, 867 (Colo.App.2008) (had the legislative body intended a statute to guarantee a particular result, it would have specifically so indicated). Nothing in the language of the regulation notifies the public that any particular event or activity is excluded from the regulation or may be authorized through other means. We do not assume the language is imprecise; rather, we conclude that the regulation means what it says-a permit is required to conduct a special activity in a park. See Colo. Water Conservation Bd. v. Upper Gunnison River Water Conservancy Dist., 109 P.3d 585, 593 (Colo.2005).
1 33 Notwithstanding the regulation's plain language, the Parks Division contends that "shall" does not mean "shall." It argues that to interpret "shall" consistent with its ordinary meaning leads to an absurd result. This is so, according to the Parks Division, because a special activities permit could not have been used in this case.
34 This argument is not persuaswe for two reasons. First, it is inconsistent with the language of the regulation, which nowhere suggests that "shall," as used in the regulation's text, should be interpreted contrary to its ordinary and plain meaning. Second, it directly conflicts with the Board's express admission that the Project "could have been handled as a special activities permit under the regulation." During the Project's extensive review, neither the Parks Division nor the Board ever concluded the regulation did not apply or that its application was absurd or illogical. Rather, for over a decade, the Parks Division, Board, and OTR-fully aware of the breadth and complexity of the Project-proceeded under the special activities regulation. The Board's later conclusion that the special activities permitting regulation was optional is thus not entitled to deference. See Tebbetts, 956 P.2d at 641 (no deference is owed to an agency's inconsistent interpretation of its regulations).
135 To the extent the Parks Division's assertion that the special activities regulation is ill-suited for an event of the Project's scope is accurate,7 any such flaw in the regulation must be addressed through formal agency rulemaking, not case-by-case decisions by the Parks Division as to whether it deems the regulation to apply. See Morton v. Ruiz, 415 U.S. 199, 235, 94 S.Ct. 1055, 39 L.Ed.2d 270 (1974) (ad hoe determinations of an agency not promulgated in accordance with rulemaking procedures cannot stand); see also Charnes v. Robinson, 772 P.2d 62, 66 (Colo.1989) (an ageney is required to proceed by formal rulemaking if it wishes to change a regulation; it cannot do so in the course of adjudicating an individual case).
136 To infuse notice and comment rule-making with any meaning, a regulation must be enforced as written. Otherwise, "if permitted to adopt unforeseen interpretations, agencies could constructively amend their regulations while evading their duty to engage in notice and comment procedures." Exportal, 902 F.2d at 50; see also Charnes, 772 P.2d at 66 (in dealing with an agency, the public is entitled to know the "rules of the game" (internal quotation marks omitted)).
137 In short, the plain language of the special activities permitting regulation is mandatory. The Parks Division's decision to abandon the regulation and approve the Pro-jeet through the Agreement is inconsistent with the regulation's plain language and is not entitled to deference.
VI. The Enabling Statute
( 38 Even so, the Parks Division and OTR contend that the broad language of section [194]*19433-10-107(1)(d) authorized the Board to approve the Project through the Agreement irrespective of the special activities regulation. See § 83-10-107(I)(d) (Parks Division may enter into cooperative agreements for the development and promotion of parks and outdoor recreation programs). It follows, they contend, that the Parks Division could unilaterally decide whether to authorize the Project through an agreement or through the permit regulation. That is, in their view, broad statutory authority trumps any regulations restraining an agency's discretion. We are not persuaded
89 If an agency promulgates regulations that are more exacting than otherwise constitutionally mandated, due process requires the agency to strictly adhere to its regulations. Dep't of Health v. Donahue, 690 P.2d 243, 249 (Colo.1984); Carpenter v. Civil Serv. Comm'n, 813 P.2d 773, 777 (Colo.App.1990); see also Otero v. N.Y.C. Hous. Auth., 344 F.Supp. 737, 745 (S.D.N.Y.1972) (an agency that ignored its own regulations effectively denied plaintiffs due process of law). "[E Iven if the applicable statutes confer complete 'discretion on agency actors, if those actors have the authority to constrain their discretion by promulgating [regulations], and they choose to do so, they have created law that can serve as the basis for judicial review." Thomas W. Merrill, The Accardi Principle, 74 Geo. Wash. L.Rev, 569, 605 (2006).
40 Department of Health v. Donahue is particularly instructive. 690 P.2d 243. In Donahue, the Colorado Supreme Court held that when a regulation "imposes on governmental departments more stringent standards than are constitutionally required, due process of law requires [agencies] to adhere to those standards." Id. at 249. Though Donahue did not specifically address whether a regulation can limit an otherwise broad grant of statutory authority, the United States Supreme Court has. E.g., Dulles, 354 U.S. 363, 77 S.Ct. 1152; Vitarelli v. Seaton, 359 U.S. 535, 79 S.Ct. 968, 3 L.Ed.2d 1012 (1959); Morton, 415 U.S. 199, 94 S.Ct.
1055, 39 L.Ed.2d 270. These cases confirm that the seope of an agency's discretion under its enabling statute is largely beside the point once the agency has adopted regulations that limit the ageney's discretion. In such instances, the agency is bound by its regulations notwithstanding broad statutory discretion. Seq, eg., Morton, 415 U.S. at 235, 94 S.Ct. 1055; Vitarelli, 359 U.S. at 540, 79 S.Ct. 968; Dulles, 354 US at 388-89, 77 S.Ct. 1152.8
¶ 41 In Dulles, for instance, the Secretary of State had broad statutory authority to unilaterally terminate Foreign Service Officers. 354 U.S. at 370, 77 S.Ct. 1152. The State Départment regulations, however, required a hearing and a recommendation for dismissal by the Under Secretary before an officer could be dismissed. Id. at 874-75, T7 S.Ct 1152, Although the regulations were initially followed, the Secretary of State ignored the hearing proceedings and terminated the employee. Id. st 376, 77 S.Ct. 1152. The Supreme Court concluded that the discharge was invalid because the Secretary of State did not follow State Department regulations. at 383, 77 S.Ct. 1152.
"Morton, 415 U.S. at 205, 94 S.Ct. 1055. 142 Likewise, in Vifarelli, the Court concluded that an agency employee was improperly discharged where the Secretary of the Interior did not adhere to the regulations for discharging an employee as a security risk. 859 U.S. at 589-40, T9 S.Ct. 968. This was so even though the employee could have been summarily dismissed without cause under executive and statutory authority. Id. Once the Secretary of the Interior treated the employee as a security risk, however, the agency's regulatlons applied. ° Id. In his opinion concurring in part and dissenting in part, Justice Frankfurter commented that "if dismissal from employment is based on a defined procedure, even though generous beyond the requirements that bind such agency, that procedure must be serupulously observed." Id. at 546-57, 79 S.Ct. 968; see also Morton, 415 U.S at 205, 94 S.Ct. 1055.
€ 43 The enabling statute here granted the Board discretion to "[eluter into cooperative [195]*195agreements with ... corporations'... for the development and promotion of parks and outdoor recreation programs." § 38-10-107(1)(d). Though the statute confers discretion on the Board to enter into such cooperative agreements, the Board promulgated specific regulations outlining a mandatory process for permitting special activities within parks.9 Nothing in the statute authorizes the Board to ignore its regulations. The statute therefore must give way to the regulation, See Vitarelli, 359 U.S. at 540, 79 S.Ct. 968; see also Exportal, 902 F.2d at 49 (rejecting agency's argument that it could disregard mandatory regulation based upon discretion conferred in statute).
{44 Nor are we persuaded by the Parks Division's and OTR's arguments that, because commercial outfitters such as fly-fishing or rafting guides are licensed to operate in the park through concession agreements rather than special activities permits, a permit was not required here. While the regulations separately contemplate concession agreements, only commercial events may be permitted through a concession agreement. 2 Code Colo, Regs. 405-1:100(b)(10).. Thus, accepting OTR's characterization of the Project as noncommercial, the Project could not have been authorized through a concession agreement. See id. In any event, the parties did not enter into a concession agreement for the Project, and therefore, that particular regulation is not at issue.
§45 Accordingly; we conclude that the Parks Division's decision to abandon the special activities permitting regulation &nd authorize the Project through the Agreement was arbitrary and capricious. VII. Project Approval Contingent upon the Bureau's Decisions |__
¶ 46 ROAR also contends that the Board's approval of the Agreement was arbitrary and capricious because it was contingent upon (1) the Bureau's approval of the Project and (2) mitigation conditions imposed in the final Environmental Impact Statement that had not been issued at the time the Board and OTR entered the Agreement. Essentially, ROAR argues that authorization of the Project was not supported by substantml evidence. We do not agree.
A. Project Review
I 47 From 1997 to 2011, the Parks Division and Board engaged in substantial analysis of the impacts-both positive and negative-of the Project. Specifically, in 2007 the Parks . Division entered into a memorandum of understanding with the Bureau and several other state and local agencies, including, among others, the Department of Natural Resources, the Division of Wildlife, the Depart ment of Transportation, the State Patrol, and county commissioners to coordinate analysis of the Project. The intent of the memorandum of understanding was to assist the Bureau in preparing an Environmental Impact Statement and to coordinate evaluation of the Project.
{48 Additionally, members of the Board visited the proposed Project sites and solicited extensive public comment on the Project. On several cccasions, the Parks Division and Board listened to OTR's presentations on the Project and heard from Project opponents, including ROAR.
149 Adverse impacts considered by the Parks Division and Board included the effect on wildlife, particularly on protected species such as bighorn sheep, golden eagles, and other raptors. And 'the permit planning team evaluated proposed wildlife mitigation measures.
. 150 The permit planning team and the Board also considered the benefits of the Project. The Board determined that the Project met the goal of promoting the parks. See 2 Code Colo. Regs. 405-7:703(2); see also § 83-10-107(1). Specifically, the Board found that the Project would enhance the recreational opportunities available to visitors, and perhaps interest a new generation of park-goers.
[196]*196€51 To examine logistical concerns, the permit planning team consulted with the Department of Transportation and local Sheriffs' offices. And the Board created an event management plan to protect the interests of the Parks Division with the understanding that OTR would cover anticipated administrative costs.
Lastly, the Board extensively reviewed the draft Environmental Impact Statement issued by the Bureau. The draft identified potential harmful impacts of the Project, but proposed ways to mitigate those impacts. The Board met often to discuss the findings of the draft and next steps.
T53 The Board ultimately approved the Agreement before the final Environmental Impact Statement was published. The Board's approval of the Project was contingent on the Bureau's authorization of the Project as well as mitigation conditions to be included in the final Environmental Impact Statement.
B. Legal Standards
4 54 Where the record, viewed as a whole and in the light most favorable to the agency, contains a reasonable basis and substantial evidence to support the agency's decision, the decision must be upheld. § 24-4-106(7); Bodaghi v. Dep't of Natural Res., 995 P.2d 288, 303 (Colo.2000) (when there is conflicting evidence the agency's determination is binding and a reviewing court may not substitute its judgment for that of the factfinder); accord Inst. for Research v. Bd. of Assessment Appeals, 748 P.2d 1346, 1348 (Colo.App.1987).
1 55 Whether the record contains substantial evidence to support an agency's final decision is a question of law, which we review de novo. Chase, N21. We defer to an agency decision involving factual and evidentiary matters within an agency's specialized or technical expertise. See Trans Shuttle, Inc. v. Colo. Pub. Util, Comm'n, 89 P.3d 398, 404-05 (Colo.2004).
T56 The special activities regulation requires review and consideration of the nature of the desired park or recreation area, the total number of anticipated visitors and vehicles expected to participate in the event, the extent to which the activity will contribute to the variety of available outdoor recreational opportunities, and the burden placed on park staff. 2 Code Colo. Regs. 405-7:708(@). A permit shall be denied for a special activity that would, among other things, have "significant adverse impact on park values, pose significant threats to the health, safety or welfare of park visitors or other person[sl, [or] be inconsistent with area management plans. . .." Id. at 405-7:708(8).
C. The Board Considered Relevant Factors
157 As the agency with expertise in the management and operation of our state parks, the Parks Division is tasked with balancing competing interests-namely, promoting the parks while still protecting wildlife, vegetation, and park ecosystems. § 33-10-101, -106.
T58 The administrative record re-fleets that the Parks Division and Board fulfilled this obligation by weighing and considering the relevant factors and competing interests to determine whether to authorize the Project. See 2 Code Colo. Regs. 405-7:708(2) (listing the factors that must be analyzed to grant a special activities permit). Specifically, the Board found that the Project would promote the parks by increasing visitors, showeasing Colorado's natural beauty, and "contributling] to the variety of outdoor recreational opportunities available." See id. at 405-7:708(2)(c). Weighed against these benefits, the Board also considered the adverse environmental impacts of the Project and public safety concerns, as well as plans to mitigate any adverse impacts.
T59 The Board ultimately concluded that the positive effects of the Project outweighed its negative impacts. We are not at liberty to substitute our judgment for that of the agency. See, eg., Bodaghi, 995 P.2d at 303 (the court of appeals erred in parsing through the record and substituting its own conclusion for that of the administrative law judge); accord Colo. Office of Consumer Counsel v. Pub. Util. Comm'n, 786 P.2d 1086, 1091 (Colo.1990). Because the record supports the Board's approval of the Project, we may not disturb it. See Nicholas v. N.Colo. [197]*197Med. Ctr., 902 P.2d 462, 473 (Colo.App.1995) (a court should uphold an agency's conclusion if it is grounded in some evidence in the record).
160 We are similarly unconvinced that approval of the Project should be invalidated because it was conditioned on the contents of the pending final Environmental Impact Statement. Nothing in the Parks Division's regulations mandates or prohibits consideration of an Environmental Impact Statement, which is a federal, not state, requirement. See Silverton Snowmobile Club v. U.S. Forest Serv., 433 F.3d 772, 780 (10th Cir.2006). Rather, the regulation specifies which factors the Board must consider, and here, the Board reviewed the appropriate factors. Cf. Citizens' Comm. to Save Our Canyons v. Krueger, 513 F.3d 1169, 1176 (10th Cir.2008) (a reviewing court must determine if the ageney considered all relevant factors). +
{61 To be sure, the Board considered more factors than required by its regulation, including mitigation proposals incorporated in the draft Environmental Impact Statement. That the Board approved the Project contingent on mitigation conditions to be incorporated in the final Environmental Impact Statement does not render its decision arbitrary and capricious or based on insufficient evidence.10 See Sierra Club v. Slater, 120 F.3d 623, 636 (6th Cir.1997) (finding that it is not necessary-to have a final, detailed mitigation plan prior to the issuance of section 404 permit under the Clean Water. Act).
T62 The Parks Division and the Bureau are cooperating agencies, each with jurisdiction over aspects of the Project. Both agen-cles considered and ultimately approved the | Project subject to their respective areas of expertise. The administrative record confirms the Board was aware of mitigation conditions the Bureau would likely include in the final Environmental Impact Statement. Thus, in these cireumstances, we do not agree that the Board's approval was not supported by sufficient evidence merely because it was conditioned upon the Bureau's approval or mitigation requirements to be included in the final Environmental Impact Statement, Id. (an agency-issued permit may be conditioned on future implementation of a mitigation plan in compliance with environmental statutes); see also Town of Superior v. U.S. Fish & Wildlife Serv., 913 F.Supp.2d 1087, 1106-08 (D.Colo.2012) (deferring to the agency's determination that mitigation measures to be later determined and implemented will meet the statutory requirement to minimize the environmental impact of any agen-ey-approved action). >
163 Accordingly, we conclude that' the Board's authorization of the Project is supported by sufficient evidence.
VII. The Project's Approval was Not Prejudicial
$64 The Parks Division lastly contends that any error in failing to comply with the special activities regulation was harmless. We agree.
T 65 "The harmless error rule applies to judicial review of administrative proceedings, and errors in such administrative proceedings will not require reversal unless [pllaintiffs can show they were prejudiced." Sheep Mountain Alliance v. Bd. of Cnty. Comm'rs, 271 P.3d 597, 606 (Colo.App.2011) (internal quotation marks omitted); accord Bar MK Ranches v. Yuetter, 994 F.2d 735, 740 (10th Cir.1993). Where the agency's mistake did not affect the outcome of the proceedings, "it would be senseless to vacate and remand for reconsideration." Jicarilla Apache Nation v. U.S. Dep't of Interior, 613 F.3d 1112, 1121 (D.C.Cir.2010). Thus, if an agency finding is reasonable and sustainable, impropriety in the process by which the decision was reached is not a basis for reversal. See Home Depot USA v. Pueblo Cnty. Bd. of Comm'rs, 50 P.3d 916, 919 (Colo.App.2002).
[198]*198T 66 True, the Parks Division did not comply with its special activities permit regulation in approving the Project. But the Board nonetheless considered all the factors required by that regulation. That is, the Board examined the nature and capacity of the park, the extent to which the Project would contribute "to the variety of available recreational opportunities, the administrative burden on staff, and the Project's potential impact on the park. As required, the Board sought, received, and considered public comment, both positive and negative. See 2 Code Colo. Regs. 405-7:703(4).11 The Board thus complied with the substance of the spe-c1a1 activities permitting regulatmn
T 67 Nothing in the administrative record supports the conclusion that the, decision would have been different had the Parks Division proceeded under its special activities regulation. ° ROAR does not identify any particular prejudice that resulted because approval of the Project was through the Agreement rather than the special activities permit regulation. O
T68 Had the special activities regulation been strictly followed, the regional or park manager would have made the final approval decision, not the Board. But the fact that a different decision-maker gave the final approval, standing alone, does not show prejudice, , An appeal of a similar procedural flaw was rejected in Schaefer v. McHugh, 608 F.3d 851 (D.C.Cir.2010). There, the plaintiff contended that the incorrect Army entity revoked the authorization for his discharge. During the administrative appeal process, the ageney determined that "any de minimis violation of regulations when the Army revoked [plaintiff's] discharge did not harm [plaintiff]." Id. at 854. The District of Columbia Cireuit Court of Appeals agreed, concluding that plaintiff failed to show any prejudice resulting from the Army's alleged error as to which entity could technically revoke authorization for his discharge. Id.
T 69 That is not to say that prejudice may never result where a decision—maker—«other than the one authorized by regulation-makes the final decision, but the administrative record must support a finding of prejudice. If the record is silent regarding prejudice, then a remand might be in order. Cf. Wagner v. United States, 365 F.3d 1358, 1359, 1364-65 (Fed.Cir.2004) (remand necessary where the administrative record lacked evidence demonstrating that the agency's failure to obtain the Secretary of the Army's pre-approval before initiating involuntary discharge proceedings against plaintiff-as required by its regulation-was harmless).
T70 But the administrative record here is extensive and clear, and contains no evidence suggesting prejudice, ROAR identifies nothing in the administrative record to support the conclusion that the regional or park manager would have acted differently and denied a special activities permit for the Project. Rather,. the record shows that as early as 1998, recognizing the Project's scope, the park manager sought the Board's input and advice on the Project. Thus, the administrative record suggests that even had the regional or park manager made the final decision, his or her determination would reflect the Board's input and recommendation. In these circumstances the administrative ree-ord supports the conclusion that had the special activities permitting regulation been followed, a permit would have issued and the, outcome would have been the same.
T71 At bottom, ROAR's disagreement with the authorization of the Project is a disagreement with the Project itself-not the process used to approve the Project. But that is not enough to establish the prejudice necessary to invalidate an agency action. Because ROAR has not met its burden of demonstrating that the Board's failure to follow the special activities permitting regulation was prejudicial, the Board's decision must be affirmed.
VIII. Conclusion
T72 The order dismissing ROAR's complaint is affirmed.
[199]*199JUDGE HAWTHORNE concurs.
JUDGE DAILEY specially concurs.