Keystone is the largest ski resort in Summit County, and one of the most popular ski vacation resorts in the United States. Its vast size and variety of terrain make it a great fit for families and groups of varying ability levels. Keystone consists of three mountains: Dercum Mountain, North Peak and the Outback, as well as five Bowls (Independence, Ericsson, Bergman, North and South Bowls) for exceptional skiing at every level. The three mountains are connected by a series of ski lifts and gondolas. Keystone vacation lodging options are plentiful, and are spread out between the two base areas. River Run is the larger, more modern base, while Mountain House, the original base area, is quieter and smaller. Keystone is the only resort in the region that offers night skiing.