It is the site of the only traffic signal (a flashing red light) in Sierra County.

According to the United States Census Bureau, the CDP covers an area of 5.0 square miles (13.0 km2), 99.98% of it land and 0.02% of it water.

This region experiences warm (but not hot) and dry summers, with no average monthly temperatures above 71.6 °F.

26 households (27.4%) were made up of individuals, and 7 (7.4%) had someone living alone who was 65 years of age or older.

There were 136 housing units at an average density of 27.1 per square mile (10.5/km2), of which 68 (71.6%) were owner-occupied, and 27 (28.4%) were occupied by renters.

[11] Federally, Sierraville is in California's 1st congressional district, represented by Republican Doug LaMalfa.