US 40 highlighted in red | ||||
Route information | ||||
Maintained by CDOT | ||||
Length | 496.442 mi[1] (798.946 km) | |||
Existed | 1926–present | |||
Major junctions | ||||
West end | ![]() | |||
East end | ![]() | |||
Location | ||||
Country | United States | |||
State | Colorado | |||
Counties | Moffat, Routt, Jackson, Grand, Clear Creek, Jefferson, Denver, Adams, Arapahoe, Elbert, Lincoln, Cheyenne | |||
Highway system | ||||
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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.