This is a container category. Due to its scope, it should contain only subcategories.

Note: the following categories currently do not exist, but may be (re-)created as needed: [Category:Companies based in Colusa County, California], [Category:Companies based in Modoc County, California], [Category:Companies based in Plumas County, California], [Category:Companies based in Sierra County, California], [Category:Companies based in Tuolumne County, California].