The Las Vegas Valley is around . All perimeters, except the northwest, are foothills or mountain ranges, with all highway routes entering the foothills; this includes the Interstate 15 to the southwest, as it climbs to Jean Pass (north), before traversing Ivanpah Valley. Only the U.S. Route 95 northwest follows an actual valley. The northwest section, thus describes the entire landform as a central, and large valley with an attached feeder valley northwest, and in this case the northwest source, and actual course of the Las Vegas Wash.