County Seal

County Info


  • Total 1,156 sq mi (2,990 km2)
  • Land 1,151 sq mi (2,980 km2)
  • Water 5.6 sq mi (15 km2)

Highest elevation[2]    7,059 ft (2,152 m)

Population (April 1, 2010)[3]

  • Total 21,419
  • Estimate (2016)[4] 21,588
  • Density 19/sq mi (7.2/km2)


Colusa County is one of the original counties of California, created in 1850 at the time of statehood. Parts of the county’s territory were given to Tehama County in 1856 and to Glenn County in 1891.

The county was named after the 1844 Rancho Colus Mexican land grant to John Bidwell. The name of the county in the original state legislative act of 1850 was spelled Colusi, and often in newspapers was spelled Coluse. The word is derived from the name of a Native American tribe living on the west side of the Sacramento River. The name was changed to Colusa shortly after.[citation needed] This, however, is disputed. The actual origin of the name is unknown.