Simultaneous to the installation of the lighthouse in 1875, a wharf and warehouses were built around the Island point to the northeast. This soon became the Lighthouse Supply and Buoy Depot for the West Coast. The entire facility included one large storehouse, two small storehouses, a paint shop, a machine shop, a wharf, a dock, and two residences for the men who worked there. Supplies needed for all twenty-eight lighthouses within the Lighthouse Department 12 passed through the depot for storage, issue, and some times just accountability/check-off. Buoys were brought to the Island for refurbishment and storage on the wharf until they were needed.
It was in 1861 that the first recommendation for garrisoning the island was made, and by the Navy rather than the Army. Fearing that a ship could sneak by Fort Point and Alcatraz in San Francisco's fogs, the Mare Island Navy Yard commandant recommended "earthworks be thrown up on Yerba Buena Island and a battery of guns planted on Point Rincon to bring a cross fire on any vessel that got past Alcatraz on the city side."
The Army engineers agreed. They included this plan in their recornmendations in 1862, proposing a gun on the island would "command the anchorage and protect the city.
When the final engineer plan was submitted a year later, spurred on by rumors of a Confederate plan to invade the harbor, two batteries were recommended for Yerba Buena Island. One would be on the eastern shore mounting heavy guns, the other on the southern shore for eight 32-pounder guns. "A temporary redoubt or block house to protect the rear of the two batteries" was proposed for the northern portion.
San Francisco businessmen provided $20,000 so that work could start immediately there and at Rincon Point, and an official request for $100,000 was dispatched to Washington. On August 11, 1863, orders directed the immediate preparations "for constructing temporary quarters near the works about to be established on Yerba Buena Island. The command will consist of one field officer and four companies. It is desirable that work should be done as rapidly as possible."
No sooner had this decision been made than a telegram was received from Washington: "works on Rincon Point and Yerba Buena Island will not be constructed at present," ordered General Henry W. Halleck, himself a veteran of the 1850's in San Francisco.
The reason for the cancellation: both points "are of too secondary importance to justify their construction while the external lines are incomplete." And, besides that, by the time a vessel came within reach of their guns, it could fire on the anchorage and the city, and the defenses would be useless.
Rincon Point was dropped without much argument. Engineers had noted that a battery there would have meant tearing down a dozen buildings Any practice firing would have toppled a warehouse and a hospital below the proposed earthworks.
But Yerba Buena Island was another matter. When General Irvin McDowell took command in 1864, the deposed hero of the Army of the Potomac reopened the battle. He mentioned Rincon Point again, but was particularly positive regarding the island.
"I wish some of the same enlightened judgment in this matter which gave us such a number of heavy guns for our Eastern works may do the same for the harbors of the Pacific coast, where they are more needed than on the Atlantic," he summarized his feelings. Remembering that previous recommendations had been vetoed by boards in Washington, he asked for permission to start at once and "require them to be carried with as much dispatch, consequently as little reference back to Washington as possible."
It was not until three years after the war that McDowell's plan was approved. A company of engineers were sent to the island and a post began to take shape on a low plateau near the eastern edge, the only area level enough for a camp. In the peacetime era, progress was slow. Two years later the camp still was "in an unfinished condition," the surgeon reported.
After an uneventful career as a "sometimes Army post" the island was turned over to a most appropriate occupant. Considering that its use had first been suggested by the Navy, it was to this service that ownership was passed and the Army days ended.
| BAK | Bakery | LAUN | Laundry |
| BOAT H | Boat House | MH | Mess Hall |
| GH | Guard House | OQ | Officer Quarters |
| H | Hospital | SH | Store House |
| K | Kitchen | SUT | Sutler |
The site is an island located between San Francisco and Oakland, in San Francisco County, California. It is also referred to as Naval Station, Treasure Island. Virtually all of the land is currently used by the Navy and the Coast Guard. The site consists of housing areas, administration buildings, gas station, paint shops, small arms magazines, transformer house and various other structures. Most of the improvements are currently used by the Navy or Coast Guard. There is an agreement between the United States and the State of California relating to the San Francisco-Oakland Bay Bridge (SFOBB) crossing at Yerba Buena Island. Approximately 13.29 acres (5.57 acres hard land and 7.72 acres airborne) of Navy property is being used for the bridge.
In 1966, by Letter of Transfer/Exchange the Coast Guard acquired 8.207 acres of land. In 1974, the Coast Guard acquired an additional 2.71 acres by Letter of Transfer, for a total disposal of 10.917 acres of land. The Department of the Navy controls the remaining 350.243 acres of land.
