Vail Pass is a 10,662 feet (3,250 m) high mountain pass in the Rocky Mountains of central Colorado. The pass was named for Charles Vail, a highway engineer.Vail Pass lies on the boundary between Eagle and Summit counties, between Vail on the west and Copper Mountain on the east. It provides the route of Interstate 70 (and earlier U.S. Highway 6) between the upper basins of the Eagle River and the Blue River, both tributaries of the Colorado River.