U.S. Highway 6 (US 6) is a part of the United States Numbered Highway System that travels from Bishop, California, to Provincetown, Massachusetts. In the U.S. state of Colorado, US 6 is an east–west highway stretching from Utah to Nebraska. Much of the route overlaps other highways in Colorado, and, as a result, much of US 6 is unsigned.

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.