At Golden Gate, only a few kilometers from Mammoth Hot Springs, this is one of the most accessible and widely seen exposures of the Huckleberry Ridge Tuff, which erupted during the first volcanic cycle of the Yellowstone Plateau volcanic field about 2.1 million years ago. This exposure of the Huckleberry Ridge Tuff is located about 20 km north from the rim of the caldera that formed as a consequence of its eruption. The Huckleberry Ridge Tuff is also found on top of Mount Everts, the broad peak 6 km in the distance. Based on the distribution of the tuff, scientists infer that a broad river valley probably existed between here and Mount Everts. The tuff filled or partly buried that valley.