TALLMAN, Circuit Judge.
We are asked to decide whether an officer had a reasonable suspicion that the driver of a car was impaired, justifying an investigatory traffic stop of that car, where: (1) the vehicle had been reported as driving erratically; (2) the officer who stopped the vehicle knew the source of the report; (3) the report described the vehicle in detail, noting the car’s color, make and model, and state license plate; (4) the report was made contemporaneously with the source’s observations of the erratic driving; (5) the officer discovered the car in the area where the report indicated that the car would likely be found; (6) the officer noticed that the driver was sitting very close to the steering wheel, a behavior the officer knew was typical of impaired drivers; and (7) the officer corroborated the report of erratic driving by observing the car weave within its lane. Given the totality of these circumstances, we hold that the district court correctly found, after an evidentiary hearing, the existence of a reasonable suspicion that the operator of the car was impaired and properly held that the investigatory stop of the vehicle was constitutional.
I
On the afternoon of September 18, 2000, Montana Department of Transportation (MDOT) employees Jay Harvey and Terry Omland were traveling eastbound on Interstate 94 outside Miles City, Montana. They stopped on the median strip of the divided freeway to pick up debris and then re-entered traffic. Harvey was accelerating their state maintenance truck to highway speed when he noticed a car approach in his rear-view mirror. The car caught Harvey’s attention because its left-turn signal light was blinking, but the car did not move to the left lane. Instead, the car straddled the center line of the two eastbound lanes. The car eventually passed Harvey and Omland’s truck while traveling in the right lane. After it passed, the driver signaled and moved over into the left lane. After it did so, Harvey and Omland noticed the car cross the yellow [1116]*1116line that ran along the median. The car passed two other vehicles and then slowly-drifted back to the right lane and across the fog line to the shoulder of the interstate. It then drifted back towards the left lane, where the driver-side tires touched the center line.
Concerned that the driver of the vehicle was impaired, Harvey and Omland decided to report their observations to the Montana Highway Patrol. In his twenty-two-year tenure at the MDOT, this was the second time Harvey had decided to report such erratic driving. Harvey radioed his MDOT dispatcher in Miles City. The MDOT dispatcher then relayed the report of erratic driving to the Montana Highway Patrol dispatcher. The MDOT dispatcher told the Highway Patrol dispatcher that “one of our guys” called in about an older model black Monte Carlo near milepost 116 on eastbound Interstate 94 whose driver was “evidently driving quite erratically.” She stated that the car had North Dakota license plates that the MDOT employee thought read “7575.” An MDOT log recorded the time of Harvey’s report as 2:18 p.m.1
Officer Calvin Schock received the report of erratic driving at 2:21 p.m. from the Billings, Montana, Highway Patrol dispatcher while he was at his office in Miles City. The dispatch conveyed the following information: a black Monte Carlo with North Dakota license plates heading eastbound on Interstate 94 was seen driving erratically near milepost 116. The dispatch also indicated that the report came from the MDOT.
Officer Schock immediately left his office and headed westbound on Interstate 94 in an attempt to locate the black Monte Carlo. Near milepost 134, Schock saw a vehicle traveling eastbound that matched the described vehicle. As the car passed, Schock noticed that the driver was sitting very close to the steering wheel, a behavior that Schock, as a veteran traffic officer with eleven years of experience and hundreds of DUI arrests, associated with impaired drivers. Schock made a U-turn and began following the Monte Carlo. He activated his cruiser’s video recorder and began filming the vehicle’s driving performance. The car matched the description radioed-in by Harvey. Soon after he caught up to the Monte Carlo, Schock noticed the car drift in its lane and then observed “one rather large movement towards the center line and then back again.”
As the patrol car got close to the Monte Carlo, the driver decided to exit into Miles City. Officer Schock stopped the car on the freeway exit off-ramp at milepost 138. At the suppression hearing, Schock explained why he stopped the Monte Carlo even though he did not personally observe the driver of the car commit a traffic violation, such as crossing the traffic lines:
I probably would have followed [the car] a little longer if it had stayed on the interstate, but as the car started to take and go off the exit right at that time, it kind of raised the bar for me a little bit because now, if we’re following it, if we do have an impaired driver, we’re going to a — I know there’s a stop sign at the end of the exit ramp. We’re getting into two-lane traffic where traffic is oncoming. And I decided it would be better, safer for everybody, if I made the stop before we got into town.
After stopping the Monte Carlo, Schock approached the vehicle to contact the driver. As Fernandez rolled down the win[1117]*1117dow, Schock immediately smelled marijuana coming from inside the car. Schock also noticed a piece of ash on the driver’s lip. After determining that the driver, Rigoberto Fernandez-Castillo (Fernandez), was in the country illegally, Schock detained Fernandez on an immigration hold. Pursuant to a state search warrant, the car was later searched, and officers discovered over 500 grams of methamphetamine hidden in a speaker cabinet in the backseat. Fernandez was indicted by a federal grand jury on one count of possession with intent to distribute methamphetamine in violation of 21 U.S.C. § 841(a)(1).
Fernandez moved to suppress the evidence found in the search on the ground that the original traffic stop was not based on reasonable suspicion and was therefore a violation of the Fourth Amendment. After a suppression hearing, the district court found that the traffic stop was justified from its inception and denied the motion.
A jury found Fernandez guilty of the drug count charged in the indictment. Fernandez appeals, arguing that the district court erred by not suppressing evidence that was fruit of the unlawful stop of his car.2 We affirm.
II
We review de novo the district court’s denial of a motion to suppress evidence. Ornelas v. United States, 517 U.S. 690, 699, 116 S.Ct. 1657, 134 L.Ed.2d 911 (1996). Factual findings of the district court are reviewed for clear error. United States v. Hammett, 236 F.3d 1054, 1057 (9th Cir.2001).
Under Terry v. Ohio, 392 U.S. 1, 88 S.Ct. 1868, 20 L.Ed.2d 889 (1968), and its progeny, an investigatory traffic stop “is permissible under the Fourth Amendment if supported by reasonable suspicion.” Ornelas, 517 U.S. at 693. In deciding whether Officer Schock had a reasonable suspicion that Fernandez was operating the Monte Carlo while impaired, which would justify the stop of Fernandez’s car, we must, as the Supreme Court has repeatedly instructed us, consider the totality of the circumstances. United States v. Arvizu, 534 U.S. 266, 273, 122 S.Ct. 744, 151 L.Ed.2d 740 (2002). All relevant factors must be considered in the reasonable suspicion calculus — even those factors that, in a different context, might be entirely innocuous. Id. at 277-78, 122 S.Ct. 744. The district court properly concluded on this factual record that the report of Fernandez’s erratic driving observed and called-in by MDOT employees, coupled with Officer Schock’s own corroborating observations, gave rise to a reasonable suspicion that Fernandez was impaired sufficient to justify an investigatory stop.
A
We begin our analysis by discussing the relevance of the MDOT report conveyed to Officer Schock. For a third-party report of suspected criminal activity to form the basis of an officer’s reasonable suspicion, that report must possess sufficient indicia of reliability. See Florida v. J.L., 529 U.S. 266, 270, 120 S.Ct. 1375, 146 L.Ed.2d 254 (2000); Alabama v. White, 496 U.S. 325, 330, 110 S.Ct. 2412, 110 L.Ed.2d 301 (1990); Adams v. Williams, 407 U.S. 143, 147, 92 S.Ct. 1921, 32 L.Ed.2d 612 (1972). For several reasons, we think the MDOT report was reliable and therefore must be considered in the reasonable suspicion calculus.3
[1118]*1118Most significantly, the report of erratic driving came from a known source: the MDOT. The MDOT dispatcher knew that MDOT employee Jay Harvey provided the report; indeed, Harvey’s name was written as the source on the MDOT log introduced into evidence at the suppression hearing.
When relaying Harvey’s report to the Highway Patrol, the MDOT dispatcher informed the Highway Patrol dispatcher that “one of our guys” called in the report and that the driver was “evidently driving quite erratically.” Although the Highway Patrol dispatcher distilled and paraphrased this information in passing it on to Officer Schock, the dispatcher’s knowledge is properly considered as part of our analysis of reasonable suspicion. See United States v. Hensley, 469 U.S. 221, 231-32, 105 S.Ct. 675, 83 L.Ed.2d 604 (1985); United States v. Robinson, 536 F.2d 1298, 1300 (9th Cir.1976); cf. Easyriders Freedom F.I.G.H.T. v. Hannigan, 92 F.3d 1486, 1497 (9th Cir.1996). Thus Officer Schock reasonably- — -and correctly — assumed that the report came from a known source, an MDOT employee who had reported seeing the erratically driven Monte Carlo. We do not believe that the dispatch conveyed to Officer Schock must have contained the magic words “this report came from an MDOT employee who personally observed the erratic driving” as opposed to “this report came from MDOT” in order for it to be considered reliable as coming from a known source.
The dissent’s argument that the tip must be considered anonymous because Schock did not know which MDOT employee made the report is unfounded. There are simply not that many MDOT employees in Eastern Montana. And certainly there are even fewer MDOT employees working near Miles City. Officer Schock testified that he knew virtually all of the MDOT employees in the Miles City area. Though the MDOT dispatcher did not disclose Harvey’s name to the Highway Patrol dispatcher, we think Harvey’s identity could easily be ascertained by a simple inquiry.4 In J.L., the Supreme Court explained that anonymous tips are often unreliable because the tipster cannot be held accountable for fabrications and the tipster’s reputation cannot be assessed. J.L., 529 U.S. at 270, 120 S.Ct. 1375. Here, because a known MDOT complainant could be held accountable for fabricating any story, the concerns raised by anonymous tips are simply not present.
At the suppression hearing, Officer Schock testified that he knew the report of erratic driving came from the MDOT. This fact was significant to Schock. Officer Schock testified that he worked closely with MDOT personnel, had received reports of traffic infractions and hazards in the past from MDOT, and had found those reports to be reliable. Because Officer Schock was familiar with MDOT personnel [1119]*1119in his area and trusted their reports, he was entitled to weigh that fact in responding to the dispatch he received. See Adams, 407 U.S. at 147, 92 S.Ct. 1921(holding that an unverified tip from a known informant was sufficiently reliable to justify a Terry stop and frisk).
Even if we assume, arguendo, that the report of erratic driving conveyed to Officer Schock was anonymous in nature, we still conclude that the report must be considered and given due weight in the reasonable suspicion calculus because the report possessed several indicia of reliability.
First, the report described the suspect car in detail. Officer Schock knew the car’s color (black), make and model (a Chevrolet Monte Carlo), and that the car had North Dakota license plates.5 Fernandez’s car matched this description exactly.
Second, the detailed report provided the “predictive information” that the Supreme Court found lacking in J.L. See 529 U.S. at 271, 120 S.Ct. 1375. The report stated that the Monte Carlo was traveling eastbound on Interstate 94 in an erratic fashion, thereby indicating that the vehicle should be found further east of milepost 116. Indeed, Schock encountered the Monte Carlo in exactly the place one would expect it to be traveling and, as discussed in the following section, moving in a fashion that indicated that an impaired driver was at the wheel.
Third, Harvey and Omland called in the report of erratic driving immediately after watching the Monte Carlo weave across traffic lines, and Officer Schock could have readily deduced the contemporaneous nature of the report. The Highway Patrol dispatcher informed Officer Schock that the black Monte Carlo was observed driving erratically while eastbound on Interstate 94 near milepost 116. After leaving his office, Schock entered Interstate 94 near milepost 135. Traveling westbound, Schock almost immediately discovered the Monte Carlo at milepost 134. Given this chain of events, and the fact that the Monte Carlo had traveled only 18 miles from the location where MDOT had observed the erratic driving, Schock could have reasonably concluded that MDOT’s observations were made only a short time before his own. Because reports made contemporaneously with a complainant’s observations are generally more reliable than those reports made later in time, Schock could assign additional credence to the dispatch he received.
We therefore hold that the MDOT report possessed certain indicia of reliability and must be given due weight in determining, under the totality of the circumstances, whether Schock had a reasonable suspicion that the driver of the Monte Carlo was impaired.
B
We do not hold that the MDOT report, standing alone, provided Officer Schock with reasonable suspicion to stop [1120]*1120the car absent Officer Schock’s own corroborating observations. That question is not before us. When determining reasonable suspicion, courts must examine the totality of the circumstances. See, e.g., Arvizu, 534 U.S. at 273, 122 S.Ct. 744. Here, other factors in addition to the MDOT report must be considered in the reasonable suspicion calculus.
After locating the black Monte Carlo described in the MDOT report, Officer Schock noticed that the driver was sitting very close to the steering wheel, a behavior that Schock knew was typical of impaired drivers. See id. at 277, 122 S.Ct. 744(explaining that due weight must be given “to the factual inferences drawn by the law enforcement officer”); Illinois v. Gates, 462 U.S. 213, 232,103 S.Ct. 2317, 76 L.Ed.2d 527 (1983) (explaining that a court’s review of evidence “must be seen and weighed not in terms of library analysis by scholars, but as understood by those versed in the field of law enforcement”). Schock testified that a driver sitting very close to the steering wheel could indicate that the driver was impaired and trying to concentrate on the road or compensate for a loss of peripheral vision due to drugs or alcohol.
Schock also observed Fernandez drift— rather appreciably as we can see on the videotape — to one side of his lane and then back to the other side. When following Fernandez, Schock drove over the same patch of road, which did have some ruts, but he did not perceive any ruts or wind that may have accounted for the Monte Carlo’s weaving since neither had any effect on Schock’s car. While weaving within one’s lane of travel is not against the law in Montana, Schock reasonably associated this type of driving as consistent with the behavior of an impaired driver.6
We are mindful of our circuit’s pre-Arvi-zu precedent that the dissent cites for the proposition that “movement within one’s own lane ... is not a sufficient ground on which to base reasonable suspicion.” But these cases are distinguishable from the case before us. Each of these cases dealt with border patrol agents who suspected that a vehicle was transporting illegal immigrants or drugs. See United States v. Jimenez-Medina, 173 F.3d 752 (9th Cir. 1999) (suspected illegal immigrant smuggling); United States v. Rodriguez, 976 F.2d 592 (9th Cir.1992) (same); United States v. Hernandez-Alvarado, 891 F.2d 1414 (9th Cir.1989) (suspected drug smuggling). It is perfectly understandable that swerving within one’s own lane of traffic would not support reasonable suspicion of smuggling, which has nothing to do with impairment, but that it would support Officer Schock’s reasonable suspicion that Fernandez was operating a vehicle under the influence of drugs or alcohol.7
[1121]*1121As a result of the MDOT report of erratic driving coupled with his own independent observations, Officer Schock had a “particularized and objective basis” to suspect that the driver of the Monte Carlo was impaired. The investigatory stop of Fernandez’s vehicle was therefore constitutional.8
C
Contrary to the dissent’s suggestion, our pre-Arvizu decisions in United States v. Morales and United States v. Thomas do not dictate a contrary result. In Morales, a Montana county sheriffs department received an anonymous tip that “a white 1989 Ford Taurus, bearing Washington license plate number 772 JJY, was transporting a pound of methamphetamine from Spokane to Missoula, Montana.” 252 F.3d 1070, 1071 (9th Cir.2001). According to the tip, the car had already left Spokane and was on its way to Missoula. Id. Assuming that the car would be traveling on Interstate 90, the most direct route from Spokane to Missoula, local deputy sheriffs set up surveillance along Interstate 90. Id. at 1072. Deputies soon spotted a white Taurus, which matched the description given by the tipster. Deputies trailed the Taurus, but the driver did not commit any traffic violations that would warrant the police stopping the vehicle. Id. Finally, after following the car for thirty-two miles, deputies stopped the car.9 Id.
In deciding that the stop of the Taurus was not supported by a reasonable suspicion of criminal wrongdoing, we noted several facts. First, the tip was from a completely anonymous source. “An anonymous tip standing alone,” we explained, “does not demonstrate an informant’s veracity or reliability because an anonymous tipster cannot be held accountable if he or she provides inaccurate information, and the police cannot assess the tipster’s reputation.” Id. at 1074(citing J.L., 529 U.S. [1122]*1122at 270, 120 S.Ct. 1375). We then explained that the anonymous tip in that case did not possess sufficient indicia of reliability such that the tip provided reasonable suspicion. In particular, we noted that the tip lacked specifics. For example, the tipster never suggested that the car would be traveling on Interstate 90. Id. at 1076 (“The tip here speaks about location in[ ] general terms by only identifying ‘Spokane’ and ‘Missoula.’ ”). We also noted that the deputies failed to corroborate the predictive information given in the tip through their own independent observations. The deputies never verified that the car was in fact traveling to Missoula, as the officers stopped the car thirty miles shy of that city. Id. at 1077(noting that although the deputies did corroborate the identity of the car with their own observations, “the tipster’s ability to identify the car does not demonstrate that he or she had knowledge of concealed criminal activity”).
In Thomas, we also declared that an anonymous tip did not possess sufficient indicia of reliability to support a finding of reasonable suspicion. 211 F.3d 1186 (9th Cir.2000). The “tip” in Thomas was forwarded by FBI agents to a local law enforcement officer in Pima County, Arizona. Agents told the officer “that he ‘might want to pay particular attention to a certain house’ in Tucson because there was ‘a suspicion that there was a possibility that there might be some narcotics’ there.” Id. at 1188. Nothing in the record indicated why the FBI suspected drugs were present at the house. Id. at 1190.
Responding to the FBI tip, local officers began surveillance. An officer noticed several people entering and leaving the house. Id. at 1188. The officer then heard three or four “thumps” coming from inside of the garage attached to the house. Id. The officer deduced from these thumps that something was being loaded into a pick-up truck. Soon after the thumping stopped, an El Camino pick-up truck exited the garage. Believing that marijuana had been loaded into the back of the El Camino, officers stopped the vehicle and subsequently discovered several packages of the illegal substance. Id. at 1188-89.
We suppressed the evidence found in the search of the El Camino after finding that the investigatory stop was not supported by a reasonable suspicion of criminal wrongdoing. First, we noted that the FBI tip “was devoid of specifics.” Id. at 1189. “[T]he information was expressed in an exceedingly equivocal and attenuated manner: the ‘suspicion’ of a ‘possibility’ that there ‘might’ be narcotics.” Id. at 1190. Perhaps more problematic, the source of the FBI tip was unknown. “The government presented no evidence regarding the basis for the FBI’s third degree of speculation.” Id. Finally, we concluded that observing people enter and leave a residence and hearing three or four thumps in a garage did not amount to reasonable suspicion that drugs were in the El Camino. Though recognizing that wholly lawful conduct may support a finding of reasonable suspicion, we held that* the sum of the observations, the noise, and the “conjectural and unsupported FBI tip” was zero. Id. at 1192. The officers, we therefore concluded, had no reasonable suspicion of criminal wrongdoing to stop the car. Id.
The investigatory stop of Fernandez’s car is plainly distinguishable from the traffic stops in both Morales and Thomas. First and foremost, the report of erratic driving conveyed to Officer Schock came from a known source, the MDOT. While it is true that we declared the FBI tip in Thomas to be anonymous in nature, it does not follow that we must dismiss the MDOT report as similarly anonymous. As we have pointed out, the Montana Highway Patrol dispatcher knew that the report originated from an MDOT employee,10 and the Highway Patrol dispatcher informed [1123]*1123Officer Schock that the report came from MDOT. The basis of the MDOT report, therefore, was from first-hand observation; and those first hand observers — MDOT employees Harvey and Omland — could be held accountable for fabricating a story. In Thomas, the record simply did not indicate any information about the anonymous source who provided the FBI its “tip.”
Second, the MDOT report possessed more indicia of reliability than either of the tips in Morales and Thomas. Unlike the tip in Morales, which did not even note the road on which the suspect car would be traveling, the MDOT report exactly described the route of the Monte Carlo (traveling eastbound on Interstate 94 from milepost 116). Officer Schock encountered the Monte Carlo precisely where one would expect the car to be traveling at freeway speeds (near milepost 134). In contrast to the tip in Thomas, the MDOT report was hardly devoid of specifics. The MDOT report described the erratically driving car in detail, noting the color, make and model, and North Dakota license plates of the suspect vehicle.
Finally, and most significantly, Officer Schock corroborated the report of erratic driving by observing the Monte Carlo weave within its lane and by noticing that the driver was sitting very close to the steering wheel. No such corroboration was present in either Morales or Thomas. In Morales the law enforcement officers never made any observations indicating that the driver of the Taurus was transporting methamphetamine. Arguably, there was some corroboration of the FBI tip in Thomas. The officer heard a thump, which he believed was the sound of marijuana being loaded into a pick-up truck. The officer also noticed several people enter and leave the residence. But in that case we recognized that the officer’s observations were simply too attenuated from the tip that drugs might be present at the residence to stop the car (the FBI tip identified that drugs might be present at the house; the report never indicated that residents of the house were transporting drugs in an El Camino) and too innocuous to factor into the calculus for reasonable suspicion of criminal wrongdoing.
Though perhaps innocent in other contexts, Fernandez’s posture and driving performance were highly relevant here. These two facts tended to show that the driver of the Monte Carlo was probably impaired, corroborating the MDOT report. This case is not a sum of zeroes, as in Thomas. The totality of Officer Schock’s observations added to the rehable MDOT report equaled reasonable suspicion sufficient to stop the car and investigate further.
Ill
Officer Schock, as an experienced traffic officer, suspected that the driver of the Monte Carlo was impaired. If Schock’s suspicion was objectively reasonable, the investigatory stop of Fernandez’s car must be upheld as the district court concluded. Given the totality of the circumstances in this case, Schock’s suspicion was reasonable. The district court properly refused to suppress evidence found in the subsequent search of the vehicle.
AFFIRMED.