Rattlesnake Island

Rattlesnake Island

1569

1742

1916

late 1930s to 1946

1966

1970s

This natural resource is a naturally-formed island in the Matanzas River.

Rattlesnake Island is a naturally occurring island on the eastern side of the Matanzas River. Just after the Spanish landing in Florida in 1569, a watchtower was built on the island for the Spanish to use as protection against attact from the south. Nearly two centuries later in 1742, a fort replaced the watchtower, called Fort Matanzas but was only is use until 1821 upon the transfer of Florida to the United States. The ruins of the fort remain on the island today.

The name Rattlesnake Island came about in the 1916 during dredging along the Matanzas River/Intracoastal Waterway was begun by the United States Corps of Engineers and/or restoration work of the fort. The name is speculated to have been taken from a nearby fishing camp, or, more likely, because of the large population of eastern diamondback rattlesnakes who live on the island. 

A major restoration project occured in 1916 by the Army Corps of Engineers. On October 15, 1924 under Calvin Coolidge, the War Department declared Fort Matanzas to be a National Monument. Then, on June 10, 1933, the Department of Interior also declared it a National Monument and both Rattlesnake Island and the remains of the fort were transferred to the care of the National Park Service on August 10, 1933. In the late 1930s restoration work began again that lasted until the mid-1940s, some which included structural shoring up of the island itself. A refresh was done in 1966 and then work was done off and on through the 1970s.

Two 1st Spanish Period middens have been located on Rattlesnake Island. Archaeological digs authorized by the National Park Service but undertaken by professors affiliated with either St. Johns River Junior College (1966) and Florida State (1975) have occured. These digs show evidence of cohabitation of Spaniards and Natives side-by-side, but no substantial evidence of pre-Spanish usages by the Timucuan or other Florida tribes.

Rattlesnake Island is part of the National Park Service System.

Rattlesnake Island is accessible to the public when they visit Fort Matanzas. For tour information, please refer to Fees & Passes - Fort Matanzas National Monument (U.S. National Park Service) (nps.gov).

Fort Matanzas is located on Rattlesnake Island.

The following books, articles, websites, and photographers were used to find the above photographs or illustrations:

Photograph 1 (1947): The Fort Matanzas Stabilization Team. “Historic Structure Report for Fort Matanzas National Monument, St. Johns County, Florida.” Denver, CO: Denver Service Center Southeast/Southwest Team, Historic Preservation Branch, National Park Service, United States Department of the Interior, November 1980.

Map 1 (March 1979): The Fort Matanzas Stabilization Team. “Historic Structure Report for Fort Matanzas National Monument, St. Johns County, Florida.” Denver, CO: Denver Service Center Southeast/Southwest Team, Historic Preservation Branch, National Park Service, United States Department of the Interior, November 1980.

Map 2 (June 1979): The Fort Matanzas Stabilization Team. “Historic Structure Report for Fort Matanzas National Monument, St. Johns County, Florida.” Denver, CO: Denver Service Center Southeast/Southwest Team, Historic Preservation Branch, National Park Service, United States Department of the Interior, November 1980.

Photograph 2 (1980): The Fort Matanzas Stabilization Team. “Historic Structure Report for Fort Matanzas National Monument, St. Johns County, Florida.” Denver, CO: Denver Service Center Southeast/Southwest Team, Historic Preservation Branch, National Park Service, United States Department of the Interior, November 1980.

Photograph 3 (2025): TBA

The following books, articles, and/or websites were used to find information about this location:

“Eastern Diamondback.” National Park Service: Fort Matanzas. June 11, 2021. https://www.nps.gov/foma/learn/nature/eastern-diamondback.htm.

The Fort Matanzas Stabilization Team. “Historic Structure Report for Fort Matanzas National Monument, St. Johns County, Florida.” Denver, CO: Denver Service Center Southeast/Southwest Team, Historic Preservation Branch, National Park Service, United States Department of the Interior, November 1980.

“Frequently Asked Questions.” National Park Service: Fort Matanzas. June 6, 2017. https://www.nps.gov/foma/faqs.htm.

Flagler College’s Rare Books, Floridiana & Institutional Repository are neither the original nor current copyright owner for the photographs. Please contact the publisher or source cited for each photograph to obtain a copy and/or permission to reproduce these items.

This record was last updated on June 4, 2025.