Sausal Creek, 3.1 miles (5.0 km) long, is one of the principal creeks in Oakland, California. The creek derives its name from the Spanish word for willow grove (sausal). Native arroyo willows were once common along its banks. Efforts are underway to restore the willows and the creek itself. A volunteer group, Friends of Sausal Creek, helps remove invasive species and plant native species. Some of the invasive species in the Sausal Creek watershed include Monterey pine trees, ivy, French broom, and wild mustard. The friends run workdays at the Scout Hut in Dimond Park on Saturdays throughout the year.