# U.S. Route 40 in Colorado

U.S. Route 40 (US 40) is a part of the U.S. Highway System that travels from Silver Summit, Utah, to Atlantic City, New Jersey. In the U.S. state of Colorado, US 40 is a major east–west route. It crosses the Rocky Mountains, passing over the Continental Divide at Berthoud Pass before descending to the Front Range. It then traverses through the Denver Metro Area, then exits by following Interstate 70 (I-70) and US 287. It is concurrent with US 287 for about 145 miles to Kit Carson. US 40 exits into Kansas east of Arapahoe in Cheyenne. At a length of almost 500 miles, US 40 is the longest numbered route in the state.

## Route description

Entering Colorado to the south of Dinosaur National Monument, US 40 runs east through the small town of Dinosaur along Brontosaurus Boulevard. The route continues a generally easterly course though Moffat and Routt counties, passing through several small communities along the way. It generally follows the course of the Yampa River. US 40 becomes Lincoln Avenue as it runs through historic downtown Steamboat Springs, Colorado.
Taking a circuitous route through Rabbit Ears Pass, Muddy Pass and Berthoud Pass (crossing the Continental Divide each time) it descends the escarpment along the eastern edge of the Rocky Mountains. Just to the east of Empire, it merges with I-70 for the first time. US 40 and I-70 will run concurrently numerous times across the U.S. The route leaves I-70 at exit 244, to the east of Idaho Springs and rejoins it again at between exits 252 and 254 in El Rancho. It parallels I-70, mostly as a frontage road, until the intersection with former State Highway 26 (SH 26) to the south of Golden
Beginning in Golden, US 40 becomes Colfax Avenue, the main east–west thoroughfare through the Denver-Aurora Metropolitan Area. Along with US 40, the entire route along Colfax Avenue is cosigned as Business Loop 70. The route travels northeast through Golden, then turns due east to travel through Lakewood, Denver, and Aurora. Among the sights to be seen along US 40 is Lake Steam Bath, once the location of a thriving health industry centered on tuberculosis sanatoriums. Also along Colfax Avenue in Denver is the Denver branch of the United States Mint, which produces 50 million coins per day. US 40 rejoins I-70 at exit 288, just to the east of Aurora.
At exit 359 in Limon, US 40 leaves I-70 along Main Street, which it shares with Business Loop 70, US 24, US 287, and SH 71. US 40/US 287 continues to the southeast to the town of Kit Carson. From there, it leaves US 287 and continues east through the towns of Cheyenne Wells and Arapahoe before entering the state of Kansas.

## Major intersections

| County | Location | mi | km | Destinations | Notes |
| Moffat | ​ | 0.000 | 0.000 | US 40 west – Vernal, Salt Lake City | Continuation into Utah |
| Moffat | Dinosaur | 2.913 | 4.688 | SH 64 east (Stegosaurus Freeway) – Rangely | Western terminus of SH 64 |
| Moffat | Blue Mountain | 11.018 | 17.732 | CR 134 – Rangely | Former SH 387 |
| Moffat | Maybell | 59.781 | 96.208 | SH 318 west – Sunbeam | Eastern terminus of SH 318 |
| Moffat | Craig | 89.322 | 143.750 | SH 13 south / CR 7 – Meeker | West end of SH 13 overlap; former SH 355 north |
| Moffat | Craig | 90.531 | 145.696 | SH 394 south (Ranney Street) | Northern terminus of SH 394; former SH 13 south |
| Moffat | Craig | 90.838 | 146.190 | SH 13 north (Yampa Avenue) – Baggs, Rawlins | East end of SH 13 overlap |
| Routt | Steamboat Springs | 130.773 | 210.459 | CR 129 (Elk River Road) – Clark, Hahns Peak, Steamboat Lake State Park, Pearl Lake State Park | Former SH 129 |
| Routt | Steamboat Springs | 134.414 | 216.318 | Mt. Werner Road | Interchange |
| Routt | ​ | 136.515 | 219.700 | SH 131 south – Oak Creek, Wolcott, Stagecoach Reservoir State Park | Northern terminus of SH 131 |
| Grand | No major junctions | No major junctions | No major junctions | No major junctions | No major junctions |
| | | 154.070 | 247.952 | Rabbit Ears Pass summit (Continental Divide) | Rabbit Ears Pass summit (Continental Divide) |
| Jackson | ​ | 157.327 | 253.193 | SH 14 east – Walden | Western terminus of SH 14 |
| | | 157.512 | 253.491 | Muddy Pass summit (Continental Divide) | Muddy Pass summit (Continental Divide) |
| Grand | ​ | 178.257 | 286.877 | SH 134 west – Toponas, Stagecoach Reservoir State Park | Eastern terminus of SH 134 |
| Grand | Kremmling | 184.529 | 296.971 | SH 9 south (6th Street) – Dillon | Northern terminus of SH 9 |
| Grand | ​ | 209.165 | 336.618 | SH 125 north – Walden | Southern terminus of SH 125 |
| Grand | Granby | 211.081 | 339.702 | US 34 east – Grand Lake, Estes Park, Rocky Mountain National Park, Arapaho National Forest | Western terminus of US 34 |
| | | 242.972 | 391.026 | Berthoud Pass summit (Continental Divide) | Berthoud Pass summit (Continental Divide) |
| Clear Creek | ​ | 257.684232.333 | 414.702373.904 | I-70 west (US 6 west) – Georgetown | West end of I-70/US 6 overlap |
| Clear Creek | ​ | 232.333– 244.260 | 373.904– 393.098 | See I-70 | See I-70 |
| Clear Creek | ​ | 244.260257.146 | 393.098413.836 | I-70 east – Denver | East end of I-70 overlap; no access from US 40 west to I-70 east |
| Clear Creek | ​ | 257.751269.441 | 414.810433.623 | US 6 east to SH 119 – Blackhawk, Central City, Golden | East end of US 6 overlap |
| Clear Creek | ​ | 271.489 | 436.919 | To I-70 west / Beaver Brook Drive – Floyd Hill | |
| Jefferson | ​ | 272.552 | 438.630 | To I-70 east | |
| Jefferson | ​ | 276.180 | 444.469 | I-70 west | |
| Jefferson | ​ | 276.9200.374 | 445.6600.602 | SH 74 east (Evergreen Parkway) – Evergreen | Western terminus of SH 74 |
| Jefferson | ​ | 0.194251.318 | 0.312404.457 | I-70 west | West end of I-70 overlap; westbound exit and eastbound entrance |
| Jefferson | ​ | 252.244 | 405.947 | Chief Hosa | I-70 exit 253 |
| Jefferson | ​ | 253.528279.244 | 408.014449.400 | I-70 east | East end of I-70 overlap |
| Jefferson | ​ | 280.570 | 451.534 | Lookout Mountain Road - Buffalo Bill's Grave & Museum, Lookout Mountain Nature Center, Boettcher Mansion | Former SH 68 |
| Jefferson | ​ | 281.977 | 453.798 | To I-70 / Grapevine Road | |
| Jefferson | Golden | 284.888 | 458.483 | I-70 BL west / CR 93 to I-70 | West end of I-70 Bus. overlap; former SH 26 (older SH 93 south) |
| Jefferson | Golden | 285.716 | 459.815 | Heritage Road | Former SH 93 north |
| Jefferson | Golden | 286.871 | 461.674 | US 6 (6th Avenue) to SH 470 – Golden, Central City | |
| Jefferson | ​ | 287.903 | 463.335 | I-70 | |
| Jefferson | Lakewood | 291.444 | 469.034 | SH 391 (Kipling Street) | |
| Jefferson | Lakewood | 292.943 | 471.446 | SH 121 (Wadsworth Boulevard) | |
| Jefferson | Lakewood | 294.273 | 473.586 | SH 95 (Sheridan Boulevard) | |
| City and County of Denver | City and County of Denver | 296.157 | 476.618 | US 287 north / SH 88 south (Federal Boulevard) | West end of US 287 overlap; northern terminus of SH 88; interchange |
| City and County of Denver | City and County of Denver | 296.792 | 477.640 | I-25 (US 6 / US 85 / US 87) / Auraria Parkway – Colorado Springs, Fort Collins | |
| City and County of Denver | City and County of Denver | 300.625 | 483.809 | SH 2 (Colorado Boulevard) | |
| Adams–Arapahoe county line | Aurora | 306.341 | 493.008 | I-225 to I-70 | |
| Adams–Arapahoe county line | Aurora | 312.142288.219 | 502.344463.844 | I-70 (US 36 west) – Denver | West end of I-70 / US 36 overlap; east end of I-70 Bus. overlap; no access from US 40 east to I-70 west |
| See I-70 for exits ||||||
| Lincoln | Limon | 359.4990.498 | 578.5580.801 | I-70 east | West end of I-70 Bus. overlap; east end of I-70 overlap |
| Lincoln | Limon | 0.000376.714 | 0.000606.262 | US 24 west – Colorado Springs | West end of US 24 overlap |
| Lincoln | Limon | 377.668 | 607.798 | SH 71 south | West end of SH 71 overlap |
| Lincoln | Limon | 378.795 | 609.611 | SH 71 north (1st Avenue) – Brush | East end of SH 71 overlap |
| Lincoln | Limon | 379.193 | 610.252 | I-70 | |
| Lincoln | ​ | 380.464386.010 | 612.297621.223 | I-70 (US 24 east) | East end of I-70 Bus./US 24 overlap |
| Lincoln | ​ | 397.833 | 640.250 | CR 109 – Genoa | Former SH 109 north |
| Lincoln | Hugo | 399.092 | 642.276 | Third Avenue | Former SH 109 south |
| Cheyenne | Aroya | 425.472 | 684.731 | SH 94 west – Colorado Springs | Eastern terminus of SH 94 |
| Cheyenne | Kit Carson | 445.142 | 716.387 | SH 59 north – Seibert | Southern terminus of SH 59 |
| Cheyenne | ​ | 446.051 | 717.850 | US 287 south – Eads | East end of US 287 overlap |
| Cheyenne | Cheyenne Wells | 470.311 | 756.892 | US 385 north (5th Street) – Burlington | West end of US 385 overlap |
| Cheyenne | ​ | 470.885 | 757.816 | US 385 south – Sheridan Lake | East end of US 385 overlap |
| Cheyenne | ​ | 486.924 | 783.628 | US-40 east – Sharon Springs | Continuation into Kansas |
| 1.000 mi = 1.609 km; 1.000 km = 0.621 mi Concurrency terminus ||||||

## State Highway 40

State Highway 40 (SH 40) represents the former two-lane alignment of US 40 in Arapahoe and Elbert Counties, prior to its demotion by the then-Colorado Department of Highways when they moved the route to then new I-70 in 1968.
SH 40 begins in Arapahoe County the town of Byers at a junction with SH 36 (N Main Street/Old Highway 36), just across the railroad tracks from downtown. It heads southeast to leave Byers and travel along the flat plains of eastern Colorado for the next several miles. The highway passes through the tiny community of Peoria, where there is an interchange with I-70/US 40/US 287 (exit 322), before passing by the Richmil Ranch Open Space park.
SH 40 then enters the town of Deer Trail, passing along the western edge of town as 1st Avenue as it has an intersection with I-70 BS (Cedar Street). It continues southeastward across the plains to leave Deer Trail and crosses into Elbert County. The highway passes through the tiny community of Lowland, where it has another interchange with I-70/US 40/US 287 (exit 336), before crossing a creek to enter the small town of Agate along 1st Avenue, with SH 40 coming to an end shortly thereafter at a junction with Main Street. Main Street (as unsigned I-70 BS) leads 0.3 miles (0.48 km) west to an interchange with I-70/US 40/US 287 (exit 340).
The entire length of SH 40 is a rural, two-lane, state highway, running parallel to both the eastbound lanes of modern I-70 to its north, as well as a railroad track to its south. SH 40 never goes beyond a half mile from the Interstate.
| County | Location | mi | km | Destinations | Notes |
| Arapahoe | Byers | 0.0 | 0.0 | SH 36 (Main Street/Old Highway 36) to I-70 (US 40/US 287) / US 36 – Strasburg | Western terminus; former US 40 follows SH 36 west |
| Arapahoe | Peoria | 6.1 | 9.8 | Peoria Road to I-70 (US 40/US 287) | I-70 exit 322 |
| Arapahoe | Deer Trail | 12.3 | 19.8 | I-70 BS (Cedar Street) to I-70 (US 40/US 287) | |
| Elbert | Lowland | 20.6 | 33.2 | CR 178 to I-70 (US 40/US 287) | I-70 exit 336 |
| Elbert | Agate | 24.1 | 38.8 | Main Street to I-70 (US 40/US 287) 1st Avenue | Eastern terminus; former US 40 continues east along 1st Avenue |
| 1.000 mi = 1.609 km; 1.000 km = 0.621 mi ||||||