Cosumnes Oaks High School (pronounced kuh-sum-ness), or COHS, is a preparatory four-year public high school in Elk Grove, California. It is the youngest high school of the Elk Grove Unified School District, opening in 2008 with the Class of 2011 being its first class of graduating seniors. In 2012 Cosumnes Oaks was officially accredited by the Western Association of Schools and Colleges (WASC). The school is named after Cosumnes River and the many oak trees in the area, creating a strong link between the school and the Cosumnes River Preserve.