Ruby Peak is a thirteener on California’s Sierra Crest near Mono Pass, in the John Muir Wilderness on the boundary of Sierra and Inyo national forests. It stands on an important divide: its eastern side drains to Rock Creek and the Owens River system, while its western slopes feed Mono Creek and the South Fork San Joaquin River. The mountain is known both for this watershed position and for its climbing history. Norman Clyde made the first known ascent before 1934 by the East Ridge, Fritz Gerstaker and Virginia Whitacre opened the West Couloir in 1946, and in 1989 Richard Leversee, Kim Miller, and Roanne Miller first climbed the difficult Technical Knockout on Ruby Wall.