OPEN ROADS! Open Roads Take the Driver into the Deep Red Rock Formations! United States highway system grew from a long history of intrepid, adventurous humans. Many of these paved highways today are the result of what were once ancient trails created by wild game, followed by American Indians, European explorers, colonists, traders, soldiers & travelers slowly widening the narrow trails through woods or improving the easiest route over a mountain pass. The automobile made Americans & the world mobile.