Camp Eighteen is an unincorporated community in Butte County, California, about 1.25 miles (2.01 km) from the Plumas County line. It lies 7 miles (11 km) north of Clipper Mills, at an elevation of 3947 feet (1203 m). The ZIP Code is 95940. The community is inside area code 530. Nearby communities are Lumpkin and Rogerville. The now-defunct Feather River Railway used to serve the area but appears to have been decommissioned. Sly Creek Reservoir is about 3.6 miles (5.8 km) southeast.