The Accidental Discovery of San Francisco Bay

San Francisco Bay from Space, August 2012. Image by  NASA.
San Francisco Bay from Space, August 2012. Image by NASA.

San Francisco today is the cultural, commercial, and financial center of Northern California, but in 1769 to a crew of weary, scurvy-ridden Spaniards who had been traversing the west coast wilderness for months, discovering the San Francisco Bay only brought disappointment. This giant bay was clearly not the Monterey Bay that King Carlos III of Spain had sent them to find.

Statue of Gaspar de Portolà, by the sculptor Josep Maria Subirachs. Photo by Bob n' Renee.
Statue of Gaspar de Portolà, by the sculptor Josep Maria Subirachs. Photo by Bob n’ Renee.

Don Gaspar de Portolá, governor of the Californias, volunteered to lead the expedition assigned to travel north from Baja California to the fabled Monterey Bay. Portolá was expected to find this bay from descriptions found in the written records by the explorer Sebastián Vizcaíno in 1602. This was to be the first on-land exploration of California by Europeans, and the men would end up traveling over 1,000 miles through unchartered terrain.

It was a high stakes mission as King Carlos and a few other European emperors were beginning to realize the importance of the Pacific Coast for maritime trade. Spain needed to establish missions and colonies along this coastline and at Monterey Bay while they still had the chance. The long journey was split into two legs: first from Baja California to San Diego and then from San Diego to Monterey.

The exploration had two crews on ships and two hardy groups of men that rode on horseback and sometimes marched on foot, all the way from Baja to Palo Alto. Both on land and sea, the first stretch of the voyage from Baja to San Diego killed many of the crew, but Portolá decided to push on with his remaining 63 men and 200 hundred horses and mules to Monterey.

The Discovery of the Wrong Bay


After setting foot in Monterey Bay and deciding this could not be the same grand bay described in Vizcaíno’s journals, the expedition marched farther north along the coast. They reached what is now the city of Pacifica on an autumn day in 1769 and decided to rest for a few days while sergeant José Ortega and his scouts went further northward to determine if they had somehow passed Monterey Bay. (They had, by a long shot.) The men, or in Portolá’s words, “skeletons who had been spared by scurvy, hunger, and thirst,” were resting in camp in what is now the city of Pacifica in San Mateo County.

Monterey Bay, California. Painting by  Albert Bierstadt .
Monterey Bay, California. Painting by Albert Bierstadt.

Ortega and his men returned with promising news of a ship anchored in a large bay to the north. The news of the ship had been gleaned from a conversation, all in sign language, with some of that area’s native people. Even though Ortega could have easily misinterpreted the sign language, Portolá was so excited by the idea that maybe, just maybe, a ship from his expedition was up ahead, full of supplies for his bedraggled men, that he decided to push forward.

Father Juan Crespi was designated chaplain and diarist for the expedition and it is from his journals that we know the bay Ortega had seen was San Francisco Bay. On November 2, 1769 Crespi wrote of “an immense arm of the sea or an estuary which penetrated into the land as far as the eye could reach … [and] beautiful plains … thickly populated with heathen villages.”

San Francisco Bay, California. Painting by  Albert Bierstadt (1871-1873).
San Francisco Bay, California. Painting by Albert Bierstadt (1871-1873).

Crespi’s journal entry described the San Francisco Bay, a much larger discovery than Monterey, but the weary crew only knew one thing: this bay did not match the descriptions in Vizcaíno’s journals. Still, the potential of a ship pushed them onward.

El Palo Alto: History’s Most Famous “Tall Stick”

The march continued on for several days until reaching what is now the city of Palo Alto. They set up camp at San Francisquito Creek beneath a tall redwood tree, now known as El Palo Alto (tall stick in Spanish). This redwood (estimated to be over 1,000 years old) is the oldest living California Historical Landmark and still stands today with a plaque at its base, commemorating the first Europeans who (albeit unknowingly) set foot on the shores of the San Francisco Bay. The city of Palo Alto was named after this tree and Stanford University chose to use the tree as the center of their seal.

El Palo Alto, circa 1910.  Iron truss railway bridge goes beside it over San Francisquito Creek, in California‎. At the time the tree was in relatively poor health due to the soot from coal powered trains, as evident by its relatively thin canopy. Photo in  public domain.
El Palo Alto, circa 1910. At the time the tree canopy was in relatively poor health due to the soot from coal powered trains.
El Palo Alto in 2004. Photo by Jawed Karem.
El Palo Alto in 2004. Iron truss railway bridge goes beside it over San Francisquito Creek. Photo by Jawed Karem.

Accepting Defeat

As most of the men rested, a few scouts were sent to further explore the area to the north, search for the ship, and confirm whether or not the large estuary was Monterey Bay. After four days the scouts returned with bad news: there was no ship; this was not the bay they sought. Portolá finally accepted defeat and turned his men back to San Diego. They carefully retraced their steps along the coast.

Fortunately, Portolá made it home alive to notify King Carlos of the “bad” news. It eventually became clear though that his discovery of San Francisco Bay greatly overshadowed his failure to find Monterey Bay. But how had Portolá and his men completely missed Monterey Bay and how had ships sailed past San Francisco Bay for 200 years without anyone realizing this valuable discovery?

Monterey Bay from Space. Image by NASA.
Monterey Bay from Space. Image by NASA.

Mission Impossible


Portolá and his men had been sent on a nearly impossible mission: to find Monterey Bay on foot with only a written description of its shape. When approaching the bay on a ship, the shape described in Vizcaíno’s notes is clear but when you look at the bay from land, it doesn’t look like a bay at all. It appears to be an open expanse of water without any safe shelter for ships to lay anchor.

The San Francisco Bay had been overlooked for two centuries because of its infamous and persistent layer of fog but also because of the contours of the land. When you sail out of San Francisco Bay, the land appears to close behind you, forming what looks like a continuous stretch of land. The addition of fog, obscuring sailors’ view, would make it near impossible by ship to see the opening to this massive bay.

  1. Sources Used

    • Crossroads: People and Events of the Redwoods of San Mateo County by Gilbert Richards. Gilbert Richards Publications. 1973.
    • El Palo Alto As It Stands Today. City of Palo Alto. Retrieved February 17, 2015.
    • Gaspar_de_Portol%C3%A0. Wikipedia.
    • History: Stanford’s identity marks have a rich history. Stanford University Website.
    • South from San Francisco: The Life Story of San Mateo County by Frank M. Stanger. San Mateo County Historical Association. 1963.
    • Returning to the memorable days of yesteryear by Kathy Bodovitz. April 13, 1994. Palo Alto Online.

About The Author

Molly Lautamo is a content strategist and writer in Santa Cruz, California. She loves exploring and researching her surroundings and then writing about her discoveries to inspire others to get out and explore too. You can check out more of Molly's writing at

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  1. Jeannette Riess

    I am currently reading Theodore E. Treutlein’s San Francisco bay discovery and Colonization, 1769-1776 published by the California Historical Society 1968, so I have found your article a rather precise summary of of the initial walk about the bay! Thank you .


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