Led by Gaspar de Portola, the expedition was looking for Monterey Bay. Its engineer, Miguel Costanso, recorded that on October 31, 1769 the party descended to a camp near a stream and marsh not far from the beach, in a hollow of high hills open only to the northwest.
On November 4 the party climbed the range to the northeast and saw what Costanso called the magnificent estuary of San Francisco Bay, the oldest European sighting of the bay. Earlier sea captains Cabrillo and Vizcaino had missed it because fog so often covers the Golden Gate. The sighting led to Spanish settlement at San Francisco. The place where it happened is now Sweeney Ridge.