Copeland Creek, Perennial stream in Sonoma County, California

Copeland Creek is a 9.0-mile (14.5 km) perennial stream that rises on Sonoma Mountain just above the Fairfield Osborn Preserve. Its middle reaches drain grazing land and vineyards on the lower western slopes of the Sonoma Mountains, and on the valley floor it bisects the campus of Sonoma State University before discharging into the Laguna de Santa Rosa. Through the city of Rohnert Park the creek is largely channelized.

The Copeland Creek watershed was home to Coast Miwok, Wappo, and Pomo peoples who inhabited the region for centuries before European arrival. Settlement from the 1800s onward brought major changes to the land and the traditional ways water was used.

The creek's name is not explained in the sources, but its lower course through Rohnert Park is largely channelized, and the Sonoma County General Plan calls for a Copeland Creek Trail linking Rohnert Park near Sonoma State University to Crane Creek Regional Park. A 2003 county plan also proposed a Copeland Creek Regional Park of about 500 acres near Fairfield Osborn Preserve.

The area is accessible through hiking trails maintained by local water management agencies with observation points along the route. Wear sturdy footwear and pay attention to seasonal changes, as water levels and trail conditions vary with rainfall.

The upper reaches feature California oak woodlands with coast live oak trees that provide habitat for endangered red-legged frogs. These amphibians depend on clean water and serve as indicators of the ecosystem's overall health.