The Carrizo Plain is a large enclosed grassland plain, approximately 50 miles (80 km) long and up to 15 miles (24 km) across, in southeastern San Luis Obispo County, California, United States, about 100 miles (160 km) northwest of Los Angeles. The southern portion of the Carrizo Plain is within the 246,812-acre (99,881 ha) Carrizo Plain National Monument, which also includes most of the Caliente Range. The Carrizo Plain is the largest single native grassland remaining in California. It includes Painted Rock in the Carrizo Plain Rock Art Discontiguous District, which is listed on the National Register of Historic Places. In 2012 it was further designated a National Historic Landmark due to its archeological value. The San Andreas Fault occurs along the eastern edge of the Carrizo Plain at the western base of the Temblor Range.

The Temblor Range is a mountain range within the California Coast Ranges, at the southwestern extremity of the San Joaquin Valley in California in the United States. It runs in a northwest-southeasterly direction along the borders of Kern County and San Luis Obispo County. The name of the range is from Spanish temblor meaning "tremor", referring to earthquakes. The San Andreas Fault Zone runs parallel to the range at the base of its western slope, on the eastern side of the Carrizo Plain, while the Antelope Plain, location of the enormous Midway Sunset, South Belridge, and Cymric oil fields, lies to the northeast.