Altamont Pass, formerly Livermore Pass, is a mountain pass in the Diablo Range of Northern California between Livermore in the Livermore Valley and Tracy in the San Joaquin Valley. The name is actually applied to two distinct but nearby crossings of the range. The lower of the two, at an elevation of , carries two railroad right-of-ways (ROWs) and Altamont Pass Road, part of the old Lincoln Highway and the original alignment of US 50 before it was bypassed c. 1937. The bypass route travels over the higher summit, at , and now carries Interstate 580, a major regional highway heavily congested by Central Valley suburbanization.