San Francisco Bay Discovery Site

Located in the town of Pacifica, California, the site of the discovery of San Francisco Bay consists of the point at which the Portola Expedition, 1769, crossed over Sweeney Ridge, and for the first time, came to view one of the world’s largest sheltered anchorages. From the top of Sweeney Ridge one can see not only inland to the Bay, but north along the ocean coast as far as Point Reyes. No structures are on the site nor are any in the immediate vicinity.

medallion showing Captain Gaspar de Portola
A historic medallion depicting Gaspar de Portola

San Diego Historical Society

In late October of 1769, Captain Gaspar de Portola and his party of sixty men (with a caravan of 200 horses and mules for riding and the pack train) had come from San Diego in search of Monterey Bay, but from their overland approach, they had failed to recognize it. They had come north, climbed over San Pedro Mountain and had made camp in Pedro Valley, now in the city of Pacifica. Though already within today’s Bay Area, they were still unaware of the Bay’s existence.

On November 1, 1769, Sergeant Ortega led a group of hunters to the top of the ridge west of the Expedition's campsite in what is now Pacifica, CA. From the ridge top Ortega saw San Francisco Bay. When Ortega returned to camp on November 3, Portola’s next move was an attempt to go around this new found “estuary” to examine the vicinity of Point Reyes visible to the north. From the camp on San Pedro Creek, Captain Portola and his men followed the beach to the north, then entered the hills and from the summit beheld the great estuary.

Three days of slow travel brought the expedition to the site of modern Palo Alto where a new base camp was made to await Ortega’s probing of the east side of the estuary. Ortega returned in four days with discouraging news. He encountered aggressively hostile Indians and observed great stretches of burned-over land leaving no pasture for the expedition’s livestock. A council was then called and the decision was made to return to San Diego.

The Portola Expedition ultimately accomplished its purpose of finding Monterey Bay. The San Francisco region was further explored by Lieutenant Pedro Fages in 1772 and by Juan Bautista de Anza in 1776. The importance of the inland bay was further emphasized by the establishment of a presidio and two missions in the environs of the bay.

Portola Site monument
This Serpentine rock monument was erected in 1968 when the site received its National Historic Landmark designation.

NPS photo

Today, the site of the “discovery” of San Francisco Bay consists essentially of two knolls from which the member of the expedition acquired the view. The total acreage of the site is approximately 18.15. There are two commemorative monuments that celebrate the Gaspar de Portola Expedition. No structures are there now nor have likely been ever there. The view of course has changed considerably with the growth of the Bay Area, now including broad industrial and residential building development. It is nevertheless a breath-taking sight to see the tremendous expanse of the Bay Area spread beneath one’s feet in one sweep.


To learn more about this area, download the parks' site bulletin on Sweeney Ridge (481.88 kb PDF).

If you are interested in learning more about the early history of the California coast and how the Spanish colonized this area, visit the National Register of Historic Places Travel Itinerary at

Last updated: March 25, 2019

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