Mount Conness, Mountain summit in Yosemite National Park, USA

Mount Conness is a mountain peak in the Sierra Nevada on the eastern boundary of Yosemite National Park. The summit rises approximately 12,590 feet and its north ridge forms a sharp dividing line along the park edge, with a small glacier visible in the higher rocky terrain.

Clarence King and James T. Gardiner made the first ascent in 1864 while working for the California Geological Survey. King, who later led the survey of the 40th Parallel, wrote that the peak's square, solid brow made it natural to name it for John Conness, the senator who had carried the bill organizing the survey.

The mountain bears the name of John Conness, a California legislator and United States Senator who supported the establishment of the California Geological Survey.

Climbers usually camp near Tioga Pass and start before dawn; a full day is needed to reach the summit. The route combines trail, scrambling and glacier travel, and the final block is class 2 scrambling along a knife-edge ridge. The summit looks east over the Conness Glacier and west toward Tuolumne Meadows.

Clarence King, who made the first ascent with James T. Gardiner in 1864, described the peak as having a "brow so square and solid" that naming it for John Conness seemed natural. The summit block is class 2 scrambling along a knife-edge ridge, with the Conness Glacier visible to the east and Tuolumne Meadows to the west.