U.S. Highway 40 (Colorado)

U.S. Route 40
Map of Colorado with US 40 highlighted in red
Route information
Maintained by CDOT
Length:	496.442 mi (798.946 km)
Existed:	1926 – present
Major junctions
West end:	US-40 at the Utah state line
	US 34 near Granby I-70 / US 6 at Empire SH 470 in Golden US 287 from Denver to Kit Carson I-25 / US 85 / US 87 in Denver I-225 in Aurora US 36 near Aurora E-470 near Aurora I-70 from Watkins to Limon US 385 at Cheyenne Wells
East end:	US-40 east of Arapahoe at the Kansas state line
Highway system
United States Numbered Highway System List Special Divided Replaced Colorado State Highways Interstate U.S. State Scenic ← SH 39 SH 41 →

In the U.S. state of Colorado, U.S. Route 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 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.

Entering Colorado to the south of Dinosaur National Monument, U.S. 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. U.S. 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 it descends the escarpment along the eastern edge of the Rocky Mountains. Just to the east of Empire, it merges with Interstate 70 for the first time. US 40 and I-70 will frequently share pavement across the U.S. The route leaves I-70 at exit 244, to the west 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 State Highway 26 to the south of Golden