This 15-acre private island offers one of the most accessible development opportunities in the Florida Keys. Situated less than 80 feet from the Overseas Highway (US-1), the property combines the seclusion of an offshore retreat with the logistical ease of a mainland lot. The island is characterized by dense forestry and a rare deed-guaranteed right of access to the highway, making it an ideal candidate for a high-end private estate, eco-retreat, or a specialized development project within the City of Marathon's jurisdiction.
Property Details
The island’s composition supports a variety of development footprints while maintaining significant natural buffers.
Upland & Wetlands: Approximately 75% of the island consists of forested upland suitable for development, with the remaining 25% preserved as native wetlands.
Development Potential: The property’s proximity to the highway allows for a simple 80-foot bridge on driveway fill or a floating barge system to establish a permanent connection.
Historical Context: A Freedom of Information Act (FOIA) inquiry with the National Archives has revealed a unique historical background involving a federal land patent, potentially relevant to buyers interested in sovereign land claims or specific historical land rights.
Land & Waterfront
The island is completely surrounded by navigable water, providing immediate Atlantic access.
Maritime Access: Canals dredged in the 1960s provide deep-water access over the reef and directly out to the Atlantic Ocean.
Shoreline: The property features a wrap-around navigable shoreline suitable for docking systems and private watercraft.
Natural Environment: The forested landscape provides a lush, tropical privacy screen, while the surrounding waters offer world-class conditions for diving, snorkeling, and sport fishing.
Access & Utilities
The property’s location provides a rare level of logistical convenience for a private island.
Transit: The island is positioned directly adjacent to Mile Marker 57, offering immediate connectivity to the amenities of Marathon and the broader Keys.
Perpetual Access: A unique deed condition from a previous landowner requires the State of Florida to provide "free access" to the highway for the property in perpetuity—a rare and valuable easement in the region.
Utilities: Given its proximity to the mainland, the island is positioned for straightforward integration with municipal power and water services compared to more remote offshore holdings.
Lifestyle & Value
Marathon Private Island offers the rare "sovereign" feel of a remote sanctuary without the traditional isolation of an island. Its unique historical status and deeded access rights make it a trophy asset in the Florida Keys market. Whether envisioned as a private family fortress or an income-producing eco-hospitality project, the property's proximity to the reefs and the city of Marathon provides an unmatched coastal lifestyle. Owner financing is available for qualified purchasers interested in securing this historically significant 15-acre estate.
