Mount Tallac, Mountain summit in El Dorado County, California.

Mount Tallac rises 9,739 feet (2,969 m) above sea level with a distinctive snow cross pattern visible on its east-facing slope during winter and spring. The peak marks a geological boundary where granite rocks of the Sierra Nevada meet older metamorphosed stone formations.

The Whitney Survey mapped the peak as Chrystal Peak. In 1877 the Wheeler Survey named it Tallac, from the Washo word daláʔak, meaning 'big mountain'.

The name Tallac comes from the Washo word daláʔak, meaning 'big mountain', given by the Wheeler Survey in 1877. The Aetherius Society counts Mount Tallac among its 19 holy mountains. The peak's snow cross appears in the opening sequence of the TV series Bonanza, filmed at McFaul Creek Meadow with the mountain in the background.

Wilderness permits are required to hike Mount Tallac; for day hikes they are free and self-issued at the trailhead. Overnight hikes in Desolation Wilderness fall under a quota, so reserve ahead, while day hiking has no quota. About 10,000 people climb the peak each year, approaching from Desolation Wilderness to the west, Fallen Leaf Lake to the east, and access roads from the north.

The Aetherius Society counts Mount Tallac among its 19 holy mountains. The peak also appears in the opening sequence of the TV series Bonanza, filmed at McFaul Creek Meadow with the mountain in the background.