Little Devils Postpile, Columnar basalt formation in Yosemite National Park, California.

Little Devils Postpile is a basalt plug made of columnar joints, standing along the Tuolumne River several miles west of Tuolumne Meadows in the Sierra Nevada, inside Yosemite National Park and eastern Tuolumne County. Its columns resemble those of Devils Postpile National Monument to the south.

Little Devils Postpile is a basalt plug, a remnant of lava that welled up and cooled in place rather than flowing away. As the basalt contracted, it fractured into columnar joints, the same process that shaped Devils Postpile National Monument to the south. The formation sits along the Tuolumne River, several miles west of Tuolumne Meadows.

The name links the columns to Devils Postpile National Monument, the larger formation of the same kind to the south in the Sierra Nevada. The basalt plug stands beside the Tuolumne River, several miles west of Tuolumne Meadows, so it is usually seen by people walking that stretch of river country in eastern Tuolumne County.

The formation sits on the Tuolumne River a few miles west of Tuolumne Meadows, in the park's eastern Tuolumne County section. Trails from the meadows follow the river through open granite country at high elevation, so carry water and expect cold nights even in summer. Snow can block routes into early summer.

The hexagonal basalt columns formed through a natural process where cooling lava fractured into regular geometric patterns. This structure mirrors the larger Devils Postpile located to the south, showcasing the same geological phenomenon on a smaller scale.