Captain Gaspar de Portolá camped October 31, 1769, by the creek at the south side of this valley and to that camp scouting parties brought news of a body of water to the east. On November 4 the expedition advanced turning inland here. They climbed to the summit of Sweeney Ridge and beheld for the first time the Bay of San Francisco.

State Registered Landmarks Nos. 24 and 394

Tablet placed by California Centennials Commission. Base furnished by County Board of Supervisors in cooperation with San Mateo County Historical Association.
Dedicated October 16, 1949