 A plaque labelled "California State Historical Landmark No.47 Anza Expedition Camp" is located at Arroyo Court, one block west on West 3rd Avenue, San Mateo.San Mateo Creek's source elevation is at almost 1,000 feet on Sweeney Ridge from which it flows southeasterly (in a valley east of Cahill Ridge and west of Sawyer Ridge) for 11.2 km (7 mi) before entering the northwest arm of Lower Crystal Springs Reservoir.