I-70 (CO)

Interstate 70
Interstate Highways in Colorado with I-70 in red
Route information
Maintained by CDOT
Length:	449.589 mi (723.543 km)
History:	Designated in 1956 Completed in 1992
Major junctions
West end:	I-70 / US-6 / US-50 at Utah state line
	US 50 in Grand Junction US 24 near Vail US 40 near Empire I-76 in Arvada I-25 / US 87 in Denver I-270 / US 36 in Denver I-225 in Aurora US 40 / US 287 in Aurora E-470 in Aurora US 24 in Limon
East end:	I-70 / US-24 at Kansas state line
Highway system
Interstate Highway System Main Auxiliary Suffixed Business Future Colorado State Highways Interstate U.S. State Scenic ← SH 69 SH 71 →

Interstate 70 (I-70) is a transcontinental Interstate Highway in the United States, stretching from Cove Fort, Utah, to Baltimore, Maryland. In Colorado, the highway traverses an east–west route across the center of the state. In western Colorado, the highway connects the metropolitan areas of Grand Junction and Denver via a route through the Rocky Mountains. In eastern Colorado, the highway crosses the Great Plains, connecting Denver with metropolitan areas in Kansas and Missouri. Bicycles and other non-motorized vehicles, normally prohibited on Interstate Highways, are allowed on those stretches of I-70 in the Rockies where no other through route exists.

The U.S. Department of Transportation (USDOT) lists the construction of I-70 among the engineering marvels undertaken in the Interstate Highway system, and cites four major accomplishments: the section through the Dakota Hogback, Eisenhower Tunnel, Vail Pass and Glenwood Canyon. The Eisenhower Tunnel, with a maximum elevation of 11,158 feet (3,401 m) and length of 1.7 miles (2.7 km), is the longest mountain tunnel and highest point along the Interstate Highway System. The portion through Glenwood Canyon was completed on October 14, 1992. This was one of the final pieces of the Interstate Highway System to open to traffic, and is one of the most expensive rural highways per mile built in the United States. The Colorado Department of Transportation (CDOT) earned the 1993 Outstanding Civil Engineering Achievement Award from the American Society of Civil Engineers for the completion of I-70 through the canyon.