The town is located on State Route 49 and is registered as California Historical Landmark #252.

[5] Settled by Mexican gold miners in 1848 and named after the Catholic parish St. Andrew, the town has been a noted mining camp since early days.

[9] According to the United States Census Bureau, the CDP has a total area of 8.4 square miles (22 km2), of which, 99.81% is land and 0.19% is water.

San Andreas has a Mediterranean climate typical of the Sierra Nevada foothills.

Winters are cool and wet with mild days, chilly nights, and substantial rainfall.

Due to the orographic effect, rainfall in all seasons is significantly greater than on the valley floor to the west.

There were 1,311 housing units at an average density of 156.2 per square mile (60.3/km2), of which 1,146 were occupied, 632 (55.1%) by the owners and 514 (44.9%) by renters.

[13] Federally, San Andreas is in California's 5th congressional district, represented by Republican Tom McClintock.