About 500,000 years ago during one of the periodic floods of the Yellowstone Caldera, lava was deposited and then exposed by the Gardner River. This basaltic flow with well-defined joints and hexagonal columns came to be known as the Sheepeater Cliffs. These exposed cliffs are composed of columnar basalt and their names reflect a band of Eastern Shoshone known as Tukuaduka (sheep eaters). Some of these exposed cliffs are near Grand Loop Road and can be reached by car, while others continue along a steep, inaccessible canyon cut by the Gardner near Bunsen Peak. The hike at Sheepeater Cliff is 0.9 miles and a moderately trafficked out-and-back trail which can quickly become a fan favorite. The path is near the Sheepeater Picnic Area and features a river; it's flat, easy, has a waterfall at the end, and is suitable for all skill levels. The trail is best used from April until November for hiking, walking, nature trips, and fishing.