College of the Siskiyous (COS) is a public community college with campuses in Weed and Yreka in Siskiyou County in Northern California. It is part of the California Community Colleges System, serving as the northernmost college in the state of California and the only college in Siskiyou County. The college is in the service area of California State University, Chico and one of only eleven community colleges in California that provide on-campus housing for students.