Massacre Rocks Rest Area

Location: Ten miles from American Falls, off of I-86 (Milepost 30.4)

History: This narrow space between rocks was referred to as Gate of Death and Devil’s Gate during the time of westward expansion on the Oregon Trail. The site earned this name because travelers following the Trail had to pass through the narrow break, making them vulnerable to potential ambushes. Diary entries suggest evidence of a clash with Shoshone Indians on August 9 and 10, 1862, which resulted in the reported deaths of ten emigrants. However, some historians believe that these skirmishes may have taken place in an area east of Devil’s Gate, and not at Massacre Rocks, as commonly believed.

Register Rock, where pioneers carved their names when passing through the area, is also on this site.

Interesting points: The Interstate highways across southern Idaho closely parallel the original Oregon Trail. From the Massacre Rocks Rest Area, an unusually fine stretch of wagon tracks can be reached by a marked trail. An historic marker explains the site.

Massacre Rocks has a rich geological history. The Devil's Gate Pass is what remains of an extinct volcano, evidence of which is easily found in the rugged lava rocks. The prehistoric Bonneville Flood shaped the landscape of the area, rolling and polishing the huge boulders found throughout the park. The flood was caused when eroding waters broke through Red Rock Pass near the Idaho/Utah border. Lake Bonneville, which covered much of what is today the state of Utah, surged through the pass and along the channel of the Snake River in a few short months. For a time, the flow was four times that of the Amazon River. It was the second largest flood in the geologic history of the world.

Statistics: The elevation of Massacre Rocks is 4400 feet. The state park is 990 acres.

Over 200 species of birds have been sited in the Massacre Rocks Park, including Canadian geese, pelicans, blue herons and bald eagles. The rich volcanic soil produces about 300 species of plants including sagebrush, Utah juniper and rabbit brush.