The Silver Strand: The Fascinating History and Fragile Ecology of Coronado's Thin Lifeline
The Silver Strand is the slender thread of sand that keeps Coronado connected to the mainland — and it has a stranger, richer history than most San Diegans realize. From its geological origins to its World War II transformation to the ecological battles being fought there today, here's the story every local should know.
In 1944, the U.S. Navy was training landing-craft crews on the Silver Strand, the same narrow ribbon of sand that beachgoers now drive along on Highway 75 every summer weekend without a second thought. The strand's history is stranger than most people expect, and it's more fragile than its broad beach suggests.
How a Sandbar Became a Highway
The Silver Strand is usually described as a tombolo, a bar of sand connecting an island to the mainland. In this case, it links Coronado and North Island to the mainland near Imperial Beach. It formed as sea levels rose after the last Ice Age, pushing the coastline into the wave shadow of Point Loma. A reverse eddy carried sediment north from the Tijuana River delta, gradually extending a sand spit until it connected with North Island. That connection is what enclosed San Diego Bay. The strand runs roughly seven miles from Coronado south toward Imperial Beach.
People were using the strand long before Coronado was a town. Archaeological sites show the Kumeyaay camped and fished there for at least 5,000 years.
The modern story began in the mid-1880s, when developers Elisha Babcock and Hampton Story launched the Coronado Beach Company and began building the Hotel del Coronado. Ferry service across the bay from San Diego began in 1886. The strand itself was put to work almost immediately. Developers graded an early road across it around 1885. A brickyard about halfway down the strand supplied bricks for the hotel, a history preserved in the name Brickyard Cove. In 1888, the Coronado Railroad completed its Belt Line, which ran from downtown San Diego around the south end of the bay and up the strand to Coronado. It carried tourists, freight, and even the hotel's garbage to a hog farm on the strand.
A concrete road followed in 1924. After the Spreckels companies donated much of the land to the state in 1931, Silver Strand State Beach opened in 1936. The strand was annexed into the City of Coronado in 1949. Until the San Diego–Coronado Bridge opened in 1969, the strand and the ferry were the only ways to reach Coronado. Today, State Route 75 follows essentially the same corridor.
The Military Transforms the Strand
World War II left a permanent mark on the Strand. In June 1943, the Secretary of the Navy authorized an Amphibious Training Base in the San Diego area to meet wartime demand for trained landing-craft crews. The base on the strand was formally commissioned in January 1944. Much of its bayside was built on fill dredged from San Diego Bay. Crews trained there deployed to the Pacific, and the base's streets are named for battles like Guadalcanal, Tarawa, and Bougainville. It was renamed Naval Amphibious Base Coronado in 1946.
The base never closed, and it became the center of naval special warfare on the West Coast. Underwater Demolition Teams have been based in Coronado since 1946, and SEAL Team ONE was commissioned there in 1962. Today, Basic Underwater Demolition/SEAL (BUD/S) training takes place at the Naval Special Warfare Center on the base. Candidates train in the cold surf of the adjacent beaches and on "the Grinder," an asphalt courtyard at the heart of the training compound.
The Navy's presence shaped what the strand looks like today. Large sections remain under military control, which has, perhaps counterintuitively, helped preserve habitat that might otherwise have been developed.
A Fragile Ecology Under Pressure
The strand's non-military portions are protected as Silver Strand State Beach, managed by California State Parks. The beach draws visitors from across San Diego County, but its ecology is under real stress.
The western snowy plover, federally listed as threatened, nests in the upper beach zone above the tide line. The California least tern, federally listed as endangered, nests in colonies on open sandy flats, including a preserve on the Navy base. Both birds depend on the same open beach that visitors want to enjoy. State Parks and the Navy both mark off nesting areas, and the Navy adjusts training schedules during nesting season. Still, the tension between access and species survival doesn't resolve easily.
On the bayside, the southern reaches of San Diego Bay support extensive eelgrass beds. Eelgrass is a nursery habitat for many fish species and a feeding ground for migratory waterfowl. The beds are tracked through regional monitoring, and they are sensitive to boat traffic, water quality, warming water, and sea level rise.
The strand faces a larger long-term threat too. Artificial dunes now help protect the bay from storm overwash, but scientists at Scripps Institution of Oceanography have warned that rising seas could eventually allow storm waves to breach the strand.
Why Silver Strand History Still Matters to Coronado Homeowners
Property on and near the strand carries value beyond square footage and view corridors. The strand is the physical reason Coronado exists as a connected community. Without it, the daily quality of life here would change fundamentally, from the drive to the mainland to the state beach to the open space buffer to the south.
Preserving the strand's ecology is also a practical concern for coastal property owners. Eelgrass beds and dune vegetation stabilize sediment and help buffer against storm surge. When those systems degrade, the costs eventually land on nearby property owners and municipal budgets alike.
For anyone considering a purchase in Coronado, understanding the strand's history and vulnerability gives useful context. Coastal access, military land use, and ecological regulation all shape what can be built, what stays open, and what the next 20 years of Coronado's coastline will look like.
The Coronado Historical Association is one of the best local resources for staying current on these issues. Its programming regularly brings together historians, scientists, and residents for grounded, community-level conversations about the places we live.
Frequently Asked Questions
How was the Silver Strand formed?
As sea levels rose after the last Ice Age, the coastline shifted into the wave shadow of Point Loma. A reverse eddy carried sand north from the Tijuana River delta, building a spit that eventually connected to North Island, forming the tombolo that encloses San Diego Bay.
What military history is connected to the Silver Strand?
The Navy authorized an Amphibious Training Base on the strand in 1943 and commissioned it in January 1944 to train landing-craft crews for World War II in the Pacific. Renamed Naval Amphibious Base Coronado in 1946, it has hosted Underwater Demolition Teams since 1946, the first SEAL team since 1962, and BUD/S training today.
Is Silver Strand State Beach open to the public?
Yes. Silver Strand State Beach, opened in 1936, is managed by California State Parks and is open for swimming, camping, and beach access. Portions of the beach are seasonally fenced to protect nesting habitat for the western snowy plover and the California least tern.
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