2021 Map of Grassy Lake Reservoir

About this map

Yellowstone National Park and the adjacent Targhee National Forest meet at a landscape defined by significant falls and high mountain hydrology. The terrain is notably marked by the Fall River and its tributaries, where remote water features like Union Falls, Terraced Falls, and Cascade Falls characterize the drainage patterns of the Pitchstone Plateau Trl. Near the southern boundary of the park, the John D Rockefeller Jr Memorial Parkway provides access toward Camp Loll and the Grassy Lake Reservoir. This 2021 survey illustrates the complex network of backcountry trails, including the Mountain Ash Creek Trl and Beula Lake Trl, which connect high-altitude lakes such as Beula Lake and Hering Lake across the Wyoming wilderness.