Written By Mauricio Segura // Photo By: Mauricio Segura
On most days, Folsom Lake looks like what it is: a busy reservoir surrounded by foothills, boats, trails and picnic grounds. But below the water sits the remains of a town that once helped turn California into a magnet for fortune seekers. Its name was Mormon Island, and when drought pulls the shoreline back far enough, pieces of its past can surface again.
The story began in March 1848, only weeks after James W. Marshall found gold at Coloma. Three members of the Mormon Battalion, W. Sidney, S. Willis and Wilford Hudson, were hunting near the South Fork of the American River when they found gold. News spread, and about 150 Mormons and other miners rushed to the area. The settlement became known as Mormon Island and grew with astonishing speed.
By 1853, more than 2,500 people lived there. This was no lonely mining camp with a few tents and muddy boots. Mormon Island had four hotels, three dry-goods stores, five general merchandise stores, an express office and many smaller shops. Sacramento County’s first recorded ball was held there on Christmas Day in 1849. For a brief stretch, the town had money, crowds and the nervous energy of a place built around the hope that the next pan of river gravel might change a life.
Then the boom began to fade. A fire destroyed the town in 1856, and it was never rebuilt. Mining settlements often rose quickly and vanished almost as fast, but Mormon Island faced a second ending nearly a century later.
Construction of Folsom Dam began in 1948. The project was built for flood control and later expanded as a multipurpose federal project serving water supply, power generation and recreation. Water was first stored in February 1955, and the old townsite was inundated as the reservoir filled.
Before that happened, the dead were moved. In 1954, the Army Corps of Engineers created the Mormon Island relocation cemetery. Remains were transferred not only from Mormon Island, but also from Salmon Falls, Negro Hill, Condemned Bar, Carrollton Bar, McDowell’s Hill, Natural Dam and Doton’s Bar. The cemetery now holds hundreds of occupied plots, preserving at least one physical connection to communities that the reservoir covered.
The lake did not erase every trace. Old foundations and scattered historic objects remain on parts of the reservoir floor. During severe drought years, receding water has exposed building remains, bricks, pottery fragments, rusty nails and other pieces of daily life. The ruins drew renewed attention in 2014, 2015 and again during the 2021 drought, when low water revealed parts of the lakebed normally hidden from view.
That visibility comes with rules. Visitors are warned not to dig, move, handle or take artifacts. The sites are protected under state and federal law, and penalties for removing protected archaeological material can be severe. The best souvenir is a photograph and the strange feeling of standing where streets, businesses and homes once stood.
Mormon Island began as a place that thousands knew, then slipped under water and out of daily memory. Folsom Lake now protects Sacramento from floods, supplies water, produces power and gives families a place to boat, fish and hike. Beneath all that modern use is an older California, one built on river gravel, risk and dreams of gold.
If you ever find yourself in Folsom the next time the lake is low enough to reveal part of Mormon Island, remember it's history. Those stones and scraps belonged to a real town. For a few years, people slept in its hotels, bought goods in its stores, danced on Christmas and searched the river for a better future. The water may hide Mormon Island for long stretches, but it has never managed to make the town disappear completely.
