Altamont is an unincorporated community

Unincorporated area

In law, an unincorporated area is a region of land that is not a part of any municipality.To "incorporate" in this context means to form a municipal corporation, a city, town, or village with its own government. An unincorporated community is usually not subject to or taxed by a municipal government...

 in Alameda County

Alameda County, California

Alameda County is a county in the U.S. state of California. It occupies most of the East Bay region of the San Francisco Bay Area. As of the 2010 census it had a population of 1,510,271, making it the 7th most populous county in the state...

, California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

. It is located 7.5 miles (12 km) northeast of Livermore

Livermore, California

Livermore is a city in Alameda County. The population as of 2010 was 80,968. Livermore is located on the eastern edge of California's San Francisco Bay Area....

, at an elevation of 738 feet (225 m), in the Altamont Pass

Altamont Pass

Altamont Pass, formerly Livermore Pass, is a mountain pass in the Diablo Range between Livermore in the Livermore Valley and Tracy in the San Joaquin Valley in Northern California...

. It was in 1969 the site of the Altamont Free Concert at the Altamont Speedway. Originally called The Summit, the name was changed to Altamont when the Central Pacific Railroad

Central Pacific Railroad

The Central Pacific Railroad is the former name of the railroad network built between California and Utah, USA that formed part of the "First Transcontinental Railroad" in North America. It is now part of the Union Pacific Railroad. Many 19th century national proposals to build a transcontinental...

arrived in 1869.

A post office operated at Altamont from 1872 to 1955.