Outdoor recreation is an important benefit provided by Federally managed and other public lands throughout the Rocky Mountains. National forests in the Forest Service, U.S. Department of Agriculture (USFS) Northern Region and Greater Yellowstone Area (a region hereafter called the Northern Rockies region) have an estimated 13.3 million visits per year; Yellowstone, Grand Teton, and Glacier National Parks account for another 8 million visits per year. National forests and national parks provide recreation opportunities at sites that offer a wide variety of characteristics. Recreation on public lands in the Northern Rockies region is inseparable from ecosystems and natural features. Whether visitors ski, hike, hunt, or camp, explore developed sites or the backcountry, or simply drive through a park or forest, natural and ecological conditions in large part determine their overall recreation experience.