Colorado Highways: US 40

Return to Routes 40-59
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Location: North Western Slope > Central Mountains > Metro Denver > Eastern Plains
Length*: 403.84mi signed; 486.92mi implied
W End: Utah border west of Dinosaur
E End: Kansas border east of Arapahoe (link to Richie Kennedy's site)
Nationally: W End: Jct I-80 near Park City, Utah; E End: Atlantic City, New Jersey (2054mi)

Counties: Moffat, Routt, Jackson, Grand, Clear Creek, Jefferson, Denver, Adams, Arapahoe, Lincoln, Cheyenne
Places: Dinosaur, Maybell, Craig, Hayden, Steamboat Springs, Rabbit Ears Pass, Muddy Pass, Kremmling, Hot Sulphur Springs, Granby, Fraser, Winter Park, Berthoud Pass, Empire, El Rancho, Golden, Lakewood, Denver, Aurora, Limon, Hugo, Kit Carson, Cheyenne Wells



Broken Route: Discontinuous due to these unmarked multiplexes with Interstates:

Mountain Passes:

Roadway Names:
Scenic & Historic Byways:

Milepost Guide:

  • 0.00: Utah border (begin US 40 in Moffat County)
  • 2.91: SH 64, Dinosaur
  • 59.78: SH 318 west of Maybell
  • 89.32: West jct SH 13 west of Craig
  • 90.53: SH 394/Ranney St.
  • 90.83: East jct SH 13/Yampa St.
  • 97.65: Enter Routt County
  • 136.51: SH 131 southeast of Steamboat Springs
  • 151.81: Enter Grand County
  • 154.07: Enter Jackson County, Rabbit Ears Pass
  • 157.31: SH 14, Enter Grand County, Muddy Pass
  • 178.25: SH 134
  • 184.52: SH 9, Kremmling
  • 209.16: SH 125 northwest of Granby
  • 211.08: US 34 northwest of Granby
  • 242.97: Enter Clear Creek County, Berthoud Pass
  • 258.26: I-70 Exit 232 interchange east of Empire (end US 40)
  • 269.44: US 6 in Clear Creek Canyon just east of I-70 Exit 244 (begin US 40 in Clear Creek County)
  • 272.21: Enter Jefferson County
  • 276.18: I-70 Exit 251 interchange west of El Rancho
  • 276.92: SH 74, El Rancho (end US 40)
  • 279.21: I-70 Exit 254 interchange, Genesee (begin US 40 in Jefferson County)
  • 284.67: I-70 Exit 259 south of Golden
  • 286.84: US 6/6th Ave. southeast of Golden
  • 287.89: I-70 Exit 262 interchange east of Golden
  • 291.44: SH 391/Kipling St., Lakewood
  • 292.94: SH 121,Wadsworth Blvd., Lakewood
  • 294.27: SH 95/Sheridan Blvd., Enter Denver County
  • 296.15: US 287/SH 88/Federal Blvd. interchange, Denver
  • 296.31: I-25 Exit 210 interchange, Denver
  • 300.62: SH 2/Colorado Blvd., Denver
  • 303.61: Begin Adams/Arapahoe County split
  • 306.34: I-225 Exit 10 interchange, Aurora
  • 312.14: I-70 Exit 288 interchange east of Aurora (end US 40)
  • Begin US 40 in Lincoln County at I-70 Exit 359 west of Limon (uses US 24 mileposts)
  • 386.01: I-70 Exit 363 interchange east of Limon
  • 422.14: Enter Cheyenne County
  • 425.47: SH 94 northwest of Wild Horse
  • 445.14: SH 59, Kit Carson
  • 446.05: US 287 east of Kit Carson
  • 470.31: West jct US 385, Cheyenne Wells
  • 470.88: East jct US 385
  • 486.92: Kansas border (end US 40)

Annual Average Daily Traffic (2008):

  • 2200 at Utah border
  • 1100 east of SH 64, Dinosaur
  • 950 east of CR 85
  • 1200 east of SH 318
  • 1300 east of CR 14
  • 14,300 at Finley Ln., Craig
  • East of SH 394, Craig (2 one-way streets): 8700 eastbound, 9500 westbound
  • 4700 east of CR 225
  • 6500 at Shelton St., Hayden
  • 5200 east of CR 27
  • 30,000 at 5th St., Steamboat Springs
  • 4600 southeast of SH 131
  • 2200 southeast of SH 14
  • 2700 southeast of SH 134
  • 6900 west of SH 9, Kremmling
  • 2100 east of CR 39
  • 3500 west of SH 125
  • 10,000 at 6th St., Granby
  • 8200 southeast of CR 522
  • 9700 south of CR 5, Fraser
  • 8000 south of Winter Park Ski Area
  • 5700 at Berthoud Falls
  • 7900 at I-70, Empire
  • 1800 at US 6, Clear Creek Canyon
  • 6400 east of I-70 Exit 247, Floyd Hill
  • 370 west of I-70 Exit 251
  • 2800 at SH 74, El Rancho
  • 1900 at I-70 Exit 254, Genesee
  • 11,600 northeast of I-70 Exit 259, Golden
  • 26,000 east of I-70 Exit 262
  • 26,900 east of Simms St., Lakewood
  • 26,600 east of SH 121/Wadsworth Blvd.
  • 32,600 east of SH 95/Sheridan Blvd., Denver
  • 35,200 east of US 287/SH 88/Federal Blvd.
  • 49,000 east of I-25
  • 42,900 east of Speer Blvd.
  • 27,900 east of Lincoln St.
  • 26,500 east of SH 2/Colorado Blvd.
  • 29,500 east of Dayton St., Aurora
  • 43,400 west of I-225
  • 26,000 east of Chambers Rd.
  • 5400 east of Tower Rd.
  • 5200 on US 40-287/Spur 24 south of I-70 Exit 359
  • 7100 east of D Ave., Limon
  • 2000 on US 24-40-297 between I-70 Exits 361 and 363
  • 3000 southeast of I-70 Exit 363
  • 5200 at 1st Ave., Hugo
  • 2200 southeast of CR 42
  • 6400 east of SH 59, Kit Carson
  • 690 east of US 287
  • 730 east of CR 34
  • 1300 on US 40-385, Cheyenne Wells
  • 860 east of US 385
  • 500 at Kansas border

Starting out at the Utah border, US 40 goes southeast to Dinosaur, and heads east through town on Brontosaurus Blvd. (seriously!). From Dinosaur, US 40 goes generally east to Elk Springs, then northeast to Maybell, and east to Craig. US 40 goes through town on two one-way streets, with westbound on Victory Way and eastbound on 4th St. From Craig, US 40 closely follows the Yampa River valley east to Hayden, and through town on Jefferson Ave. Heading east US 40 then passes through Milner.

Next stop is Steamboat Springs. "Steamboat", as the name is often shortened to, is the largest city in the northwestern part of the state and a major tourist destination. Known mostly as a ski resort, the town is also a popular summer destination. US 40 uses Lincoln Ave., the main drag right through downtown. Heading southeast out of town, US 40 has a brief expressway section with an interchange at Mount Werner Rd., the chief access to the ski resort base area northeast of town.

US 40 then heads south out of town, but south of the junction with SH 131 begins climbing up the side of the Gore Range toward Rabbit Ears Pass. US 40 gains an incredible 2500' in about 7 miles, utilizing a steep but fairly straight alignment, all the while having an expansive view of the Yampa River valley and Lake Catamount. Heading east up Rabbit Ears Pass you approach what appears to be the summit at the top of the grade, but it is actually a false high point at 9400'. US 40 then spends almost 8 miles traversing rolling alpine meadows along Walton Creek until reaching the true summit of Rabbit Ears Pass at 9426' and crossing the Continental Divide. Off to the north is the rock formation that gave the pass its name, which from some angles does sort of resemble rabbit ears.

Just 2 miles later, US 40 goes through Muddy Pass at the junction with SH 14, again crossing the Continental Divide. Due to the topography of the area, Muddy Pass isn't really a typical pass. It's actually downhill the whole way from the summit of Rabbit Ears Pass to the "summit" of Muddy Pass. Little Muddy Creek is practically within spitting distance of US 40 for awhile, even though it is on the opposite side of the Divide from US 40. Not only does US 40 cross the Continental Divide twice in the course of 2 miles, it changes counties three times (Routt to Grand to Jackson to Grand) within 6 miles. All in all an interesting stretch of highway.

From Muddy Pass US 40 descends down Little Muddy Creek and into the valley for Muddy Creek. A good chunk of the way between the base of the pass and SH 134 it has an oddball 60mph speed limit. US 40 follows the meandering Muddy Creek southeast toward Kremmling, passing Wolford Mountain Reservoir along the way. Park Ave. is what US 40 is on through Kremmling, and takes an abrupt easterly turn at that town, then follows the Colorado River upstream.

West of Hot Sulphur Springs US 40 passes through the fairly short Byers Canyon, which just sort of materializes out of nowhere as you're driving into it. In Hot Sulphur Springs, US 40 utilizes Byers Ave., then heads east to Granby, uses Agate Ave., and then starts going southeast. Tabernash, Fraser, and Winter Park are stops along the way, and just south of Winter Park US 40 hits West Portal, the west end of the impressive Moffat Railroad Tunnel, directly adjacent to the Winter Park/Mary Jane ski area.

Berthoud Pass is south of Winter Park, and is maintained throughout the winter. Eastbound up the pass there is a second climbing lane for slower vehicles, as well as westbound up the pass. I count at least 14 switchbacks going over Berthoud Pass. US 40 then follows West Fork Clear Creek down east to Empire, and just east of that merges with I-70 at Exit 233, and disappears. Westbound approaching Exit 233, drivers are advised that they can use either I-70 or US 40 to get to Salt Lake City.

If you pay attention to the signing on I-70, the next place eastward that US 40 will appear is Exit 259 south of Golden, where Colfax Ave. starts, and curves northeast, then east into the west metro. However, there are a couple of sections of old US 40 left along side of I-70 between Idaho Springs and Golden. These sections are not mentioned on the mainline of I-70, but they are signed on US 40 itself. The first section starts at US 6 in Clear Creek Canyon, just east of where US 6 hits I-70 at Exit 244. That section continues east along I-70's north side, then crosses over to I-70's south side at the Exit 251 half diamond west of El Rancho. US 40 then goes east to El Rancho, ending at SH 74 just south of Exit 253. El Rancho is basically a cluster of buildings around that intersection, and that intersection is a signal light, congested with lots of commuter traffic.

The second section of old US 40 still maintained is in Mount Vernon Canyon. It starts at Exit 254, the Genesee Park exit, then travels down Mount Vernon Canyon on I-70's north side, to Exit 259 where it is signed again on I-70. If you get off I-70 at Exit 256 (Lookout Mountain) and turn north, you will be greeted with a "40 <->" sign.

Exit 259 is signed differently depending on which direction you're going on I-70. Eastbound it's called "[US 40] [BL 70] Golden Morrison" but westbound it's "Morrison". From Exit 259, US 40 is concurrent with BL I-70 along Colfax Ave. all they way through metro Denver. From the area of Golden, US 40/BL 70 is five- lane undivided east into Lakewood. Also there is a partial cloverleaf interchange with US 287/SH 88 at Federal Blvd. East of that, trailblazers line Colfax top to bottom with a BL 70 shield, then US 40, then US 287. Colfax goes through I-25 Exit 210, then enters downtown Denver, and passes the State Capitol. Colfax continues due east, and finally merges again with I-70 at Exit 288. This is BL 70's east end, and US 40 and 287 disappear there. Urban legend is that Colfax Avenue is the longest street in the US, but that's not true.

Going east on I-70, you won't see US 40 again until you get to the west side of Limon. At Exit 359, US 40 breaks off of I-70, along with US 287, and goes south along what is defined as Spur SH 24 in CDOT sources (built when I-70 was completed through there in the 1960s) to the historic routing of US 40-287 west of Limon. The route from I-70, south to US 24, then east through on Main St. Limon carries the BL I-70/US 24-40-287 designation. There is one stretch that is also multiplexed with SH 71.

Going through Limon, they then emerge on the east side of town and curve northeast, pass through I-70 Exit 361, then curve back to the southeast hitting I-70 Exit 363. There, US 24 disappears, while US 40-287 heads southeast toward Kit Carson. Hugo, while a pretty small town, is the Lincoln County seat and has a hospital. Southeast of Hugo US 40-287 has a rest area, which is sort of out on its own in the middle of nowhere. Wild Horse is next, which is a blink-or-you'll-miss it collection of buildings. In Kit Carson, US 40-287 goes through as the divided 3rd St., then just east of town US 287 curves south while US 40 breaks off and goes east. US 40 heads east to Cheyenne Wells, which as far as Eastern Plains towns go is fairly sizable. There US 40 has an overlap with US 385 for a few blocks, then US 40 continues east, and east of Arapahoe, it crosses over into Kansas.

While US 40 doesn't have a lot in the way of towns east of Limon, the section with US 287 northwest of Kit Carson is a major trucking route, meaning there is a fair amount of traffic and prompting CDOT to keep it in pretty decent shape.

US 40 is the famous cross-country "National Road."

Photo Gallery:

US 40 is an original 1920s US highway, going from Utah through Craig, Steamboat Springs, Kremmling, Granby, Georgetown, Denver, Bennett, and to Limon. East of Limon US 40 had a north/south split, with US 40N heading into Kansas via current US 24, and US 40S going via current US 40 to Kansas. Below is part of an e-mail from Richie Kennedy, who found this historical info at the Spencer Library. It explains how the US 40N/S split came about because of a dispute over the routing of US 40 in western Kansas:

From "Milestones : a history of the Kansas Highway Commission & the Department of Transportation" by Sherry Lamb Schirmer, Dr. Theodore A. Wilson.

... The dispute rose over the line of U.S. Highway 40 to Colorado -- obviously a juicy prize for the lucky towns it would connect since U.S. 40 would be a key tourist route to the Rockies. Feelings also ran high over U.S. 40 because it involved the Victory Highway. Victory was a latecomer among the voluntary associations of marked trails. It was begun as a memorial to America's World War veterans in the early 1920s. By 1925 the necessary work on the Kansas portion of this transcontinental line was nearly done, with the first hundred miles west of Kansas City paved or gravelled, its central portion partly paved and its western end well-graded.

Victory Highway looked like the natural choice to be a U.S. highway, but central Kansans were outraged when the Joint Board extended U.S. Highway 40 along the Victory Highway only as far as Manhattan. At that point, the route angled northwest to strike the Midland Trail and continue west to the Colorado line at Kanarado. [The remainder of the Victory Highway would have been US 340, per Robert Droz's 1925 BPR plan -- Richie Kennedy] Since this brought U.S. 40 through Commissioner Davidson's hometown of Glasco, the by-passed cities suspected a sell-out. Said one irate resident, "Of all the stealing that was ever perturbed on the American people, that deal wherein Ben Paulen and the State Highway Commissioners stole the Victory High-Way from us going North from Manhattan is the biggest.... Now if Ben Paulen thinks he is going to get by with that kind of stuff here in Saline County, he is badly mistaken. From our stand point it looks to me like first degree murder."

Agriculture Secretary Jardine heated the controversy to a boil in early December, 1925, when he sent the bypassed towns copies of a telegram from the Kansas Highway Commission which purportedly asked that U.S. 40 be rerouted north from Manhattan. According to Jardine, the entire Victory line originally had been designated Highway 40. Commissioner Gardner stoutly denied to reporters that the Kansas commission had had anything to do with federal markings, but protests from Junction City, Salina, and Abilene grew so angry that Paulen, Gardner and Buck met with the "Victory people" on December 18, 1925. A compromise later was reached whereby the northern route was made U.S. 40 North and the Victory Highway was designated U.S. 40 South from Manhattan to the Colorado line in Wallace County. At that point the rivalry turned into a competition for highway aid and tourist traffic -- each route advertising itself the shorter, more scenic way to the West.

The US 40N/S split was eliminated in 1936, with US 24 on the north and US 40 on the south. US 40 was paved all the way across the state by 1938, with only Rabbit Ears Pass not paved. That was paved by 1950.

A major reconstruction project rebuilt US 40 over Rabbit Ears Pass in 1960. See this Steamboat Today article sent to me by Randall Gaz for more. Portions of the old road on the west side of the pass are still visible in aerials.

The expressways on the west side of Lakewood and the east side of Aurora were complete by 1957. The Idaho Springs freeway bypass was complete by 1960, as was the interchange at Federal Blvd. in Denver. During the 1960s, I-70 began replacing US 40, so see that listing for more info.

Between Idaho Springs and Golden, the old sections of US 40 still on the state payroll have been in a state of flux since I-70 was built:

On Berthoud Pass, the major reconstruction and widening on the east side to add a westbound climbing line was done in two phases. The upper three miles was completed in 2002 and lower three miles was completed November 20, 2006.

See also SH 40 and SH 36.


Last updated 9 March 2014