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. Black Gore Creek, a tributary of Gore Creek, in the watershed of the Eagle, descends from the north side of the pass towards the town of Vail. West Tenmile Creek, in the watershed of the Blue, descends from the south side. The pass is significantly steep on either side (7 to 8%), and two runaway truck ramps are available on the west bound side for trucks.