Dolores. The hills jut up from the harbor, and homes fill the small valleys and dot the lower slopes of Telegraph Hill, Nob Hill, and Rincon Hill. Rincon Point, set aside as a military reservation, marks the bottom of Yerba Buena Cove.
View of Black Point (just west of North Beach) from Telegraph Hill—1866. —Library of Congress
South Beach—yes, there was a South Beach—provides an ideal environment for shipbuilding and repair. The gently sloping beach, protected by low sand cliffs, makes it easy to drag a boat out of the water and to launch it again. The moon-shaped beach extends between Rincon Point and Steamboat Point to the south.
South Beach was the center for ship and boat building and repair. —Library of Congress
Looking out at Steamboat Point from South Beach in 1866. —Library of Congress
Mission Bay, just below Steamboat Point, offers access to the Mission region via Mission Creek. The creek runs near Mission Dolores, emptying midpoint into the bay. Only shallow-draft boats can use the tidal bay, and any boat can be stranded by a low tide. Inland rolling sandhills, pastures, marshland, creeks, and ponds make up the landscape. The area is called Potrero Nuevo or “new pasture,” because it was originally pastureland set aside for use by the local inhabitants, according to Spanish law. This area includes Potrero Hill, which terminates at Potrero Point in the bay, and marks the bottom of Mission Bay. Potrero Nuevo terminates at Islais Creek.
Potrero Viejo, “old pasture,” starts below Islais Creek and was added to the Bernal land grant that extends from there to modern day Hunters Point (a long finger of land) and Bernal Heights. The creek defies description and, as such, is optionally referred to as a navigable creek, a bay, a tidal basin, or an non-navigable swamp. The name Islais (pronounced “iss-lis” as in “bliss” and “list”) is not Spanish and is said to be the Ohlone Indian word for the wild cherry trees found growing in the area. The inlet, or bay, was called Islais Creek or Islais Creek Bay depending on the speaker’s perspective and the tide. It reads about three feet deep at average high tide and it is bare mud at low.
The land below Hunters Point to what is now Candlestick Point, San Francisco’s southern border, can be described simply as mudflats, which held little interest for the early locals. Valuable but unusable wetlands, no one even bothered to begin filling them in until the mid-twentieth century.
South Beach from Steamboat Point—1866. —Library of Congress
ISLANDS AND ROCKS
San Francisco Bay quickly evolved into a critical shipping port after the discovery of gold. Nearly all of California’s wealth funneled through the Golden Gate. The local, state, and federal governments responded quickly to any hazard to navigation. Blossom Rock became the first shipping hazard identified as requiring a permanent solution and the solution turned into a citywide event.
Islais Bay and Creek prior to filling the wetland. Note the plank walkways used to access boats at both high and low tides. —Photo courtesy of San Francisco History Center, San Francisco Public Library
Blossom Rock lay just five feet below the waterline a half-mile northeast of North Point (near Pier 39). It was part of a four thousand-foot crescent consisting of four underwater rocks starting at Blossom Rock, then continuing to Harding Rock, Shag Rocks, and Arch Rock and terminating at Alcatraz Island. Ideally placed to waylay or even rip the hull from any unwary ship, Blossom Rock was first named and charted as a navigation hazard by Captain Frederick W. Beechey on the HMS Blossom, a British man-of-war visiting San Francisco in 1826. Legend claims the Blossom located the rock by striking it, but there is no documentation confirming that event. Regardless, many a ship has encountered the rock, both before it was charted, and since. An East India ship, the Seringapatam, ran aground on Blossom Rock in the early 1830s, waiting until the tide turned before she could slide off and continue her voyage. Her teakwood hull saved her from serious damage.
The U.S. Army Corps of Engineers began test explosions on Blossom Rock in early 1867 in the hope that it could be topped off to a depth of twenty-four feet. The Corps determined that the approximately 105- by 195-foot underwater peak could be demolished and proposed a budget of $50,000 to accomplish the task.
Alexis W. Von Schmidt, a civil engineer and builder of the first dry dock in San Francisco, proposed using a similar method to remove the underwater impediment as that used for the dry dock. Von Schmidt asked for $75,000 to accomplish the task. The Corps awarded him the contract, to be paid after assurance that twenty-four feet of clearance had been achieved.
Von Schmidt’s team built a square crib at the wharf and then floated it out to the rock. The crib was anchored to the rock and then solid supports were used to fix it rigidly to Blossom Rock. Von Schmidt used the new technology he had devised to build the Hunters Point dry dock, and in October of 1869, he lowered a boiler-iron cylinder nine feet in diameter and thirteen feet tall down to the underwater peak to create a coffer dam, and then sealed it and pumped it dry. His team then inserted a six-foot diameter, seventeen-foot tall pipe inside the first and began the excavation. They excavated downward into the rock to a depth of fourteen and a half feet from the bottom of the dam. From that point, the rock was excavated horizontally to form a cavern sixty feet wide and one hundred forty feet long, with a domed ceiling of twelve feet. Rock columns that had been left for support were replaced with eight-inch by ten-inch wooden beams.
On April 20, 1870, the team began the arrangement of thirty-eight sixty-gallon barrels and seven boiler-iron tanks around the perimeter of the cavern, each one filled with sodium nitrate blasting powder and waterproofed with asphalt. After connecting all with gas pipe and rubber tubing up to the crib on the surface, the underground activity ceased and the cavern flooded with bay water. Von Schmidt announced that the rock would be blown on April 23, 1870.
Blowing up Blossom Rock in San Francisco Bay. —Author’s collection
On that day, thousands of spectators, radiating a holiday spirit, gathered on Telegraph Hill to gain a clear view of the great spectacle. Shortly after two in the afternoon, a boat played out the single insulated wire and anchored eight hundred feet away from the crib. The wire was attached to each of the detonators set to the twenty-one and a half tons of explosives. The salt water of the bay served as the return to complete the connection.
At three-thirty that afternoon, a twist of the crank on the magneto-battery initiated an explosion that sent a column of water and rock shooting upward from two hundred to five hundred feet into the air, depending on who did the reporting. The main black column coming up from the cofferdam was surrounded by shorter columns of debris and water that marked the perimeter of the cavern below. Pieces of rock and timber seemed suspended in air before gradually falling back to the bay. The crowds cheered, and the next day newspapers printed enthusiastic accounts of the event.
Soundings indicated that the results were two feet short of the goal. The Army Corps of Engineers refused payment until
