Crushing visitation has also fueled an expanding human footprint outside the park%2C such as in Gardiner%2C Montana%2C northern gateway to Yellowstone%2C pictured here. More development at the edge of Yellowstone further constricts the ability of wildlife to move in and out of the park. And sold-out campgrounds and hotels in the park mean more people are turning to Forest Service campgrounds and that means more recreation pressure. Photo courtesy Jacob W. Frank%252FNPS