February 12, 2020

The Matheson House serves as a museum and state park office.

FLORIDA STATE PARKS The Matheson House serves as a museum and state park office.

ISLAMORADA — Four highway bridges and one private causeway can be found along the U.S. 1 stretch linking Upper and Lower Matecumbe keys, a distance of just over two miles.

The number of waterway roads could have increased even more had a 1960s plan to build a bridge to Lignumvitae Key come to fruition.

A causeway to Lignumvitae Key proposed in the 1960s would have created a mile-long cut through an area now protected by the state as an aquatic preserve.

In the mid 1960s, then-owners of Lignumvitae Key filed for a state permit to build a one-mile causeway to the 280-acre island they had purchased from the Matheson estate a decade earlier, reportedly for $125,000.

“They wanted to develop hotels and all that jazz,” Katy Cummings, Florida Keys Aquatic Preserves manager for the state Department of Environmental Protection, said during a Jan. 16 meeting. “The plan was to do dredge and fill. … The local people got pretty upset about that.”

Jerry Wilkinson, founder of the Historical Preservation Society of the Upper Keys and author of KeysHistory.org, wrote, “In the mid-1960s, development and causeways were proposed for both Indian and Lignumvitae Keys. Obviously, neither was developed. Local citizens protested the proposals and both islands ended up as Florida state parks.”

Florida Keys residents who objected to the Lignumvitae causeway may have been carrying memories of a lethal disaster three decades in the past.

In addition to the four bridges between the Matecumbe keys, three highway causeways — now commonly known as “the Indian Key Fills” — were largely created by using dredged fill during construction of Henry Flagler’s Overseas Railroad.

The stretch also has the quarter-mile-long privately owned causeway to Tea Table Key.

“Some of the devastation to portions of Upper and Lower Matecumbe Key during the 1935 Labor Day Hurricane is attributed to the poor design of Flagler’s railroad between the two islands,” a 1991 state Department of Natural Resources report says.

“Newspaper reports from that era postulate the theory that the length of the two islands created a barrier to the 15-foot storm surge that made landfall before the storm,” the document continues. “The large expanses of filled causeway between the two islands further restricted the only ‘safety valve’ for the passage of storm waters.

“The fill created a dam that backed storm waters even higher along both shorelines until it overwashed portions of both islands, causing great loss of life and property. Large sections of Flagler’s Overseas Railroad were also lost, never to be rebuilt.”

Indian Key Historic State Park is well-known for the deadly 1840 attack on what was once a sailing community that served as the county seat for an area covering nearly half of Florida.

Lignumvitae Key Botanical State Park has become celebrated for preservation of its lush subtropical growth.

“The virgin tropical hardwood hammock that thrives on this island was once common on most of Florida’s Upper Keys,” describes the Florida State Parks website. “Most of these forests have been lost to development on other islands.”

In 1919, William J. Matheson, a wealthy Miami chemist who specialized in making commercial dyes, bought Lignumvitae Key, named for the dense and heavy tree. Matheson cleared about three acres and built a caretaker’s home that still stands.

Non-native plants and animaIs were brought to the island, but now the mostly restored hardwood hammock supports 65 species of native rare trees and shrubs.

“The tropical hardwood hammock that thrives on Lignumvitae Key is one of the few remaining virgin forests of its type in Florida’s Upper Keys,” a DEP summary says. Visitors touring the hammock are guided by a park ranger to protect the vegetation.