The winning bid was $2,769 by Paul Sawyer, acting as an agent for longtime state Rep. Bernie C. Papy Sr., known as the King of the Keys. He took over the warranty deed for $6,100 in early 1952.

“The honorable Papy knew everyone,” Naja Girard said. “And he knew the Navy was planning on putting a fuel depot with tanks on Wisteria Island.”

The Navy didn’t end up needing Wisteria, but Papy still made a nice profit. He sold Wisteria in 1956 for $115,500 to Connecticut businessman Amaryk Aldo. Six years later, it changed hands again, purchased by a mystery group of six men known as Wisteria Island Inc. They, too, did nothing with the island, finally agreeing to sell it for $160,000 to Key West native David Wolkowsky and his partner, Clayton Partin.

“We had big, big plans,” said Wolkowsky, now 93. They hired the New York firm that designed the Lincoln Center. It came up with a luxury complex that was eye-popping at the time: 60 homes, a yacht club and a three-hole golf course.

Wolkowsky said he borrowed $20,000 from Ben Bernstein to complete the sale. But when he asked for an extension to repay the loan, Bernstein would not give it to him and instead took over the purchase agreement in 1967. “I never knew there was any problem with the title,” Wolkowsky said.

Ben Bernstein had considered creating a houseboat row on the island, but he died in 1973. His widow, Miriam, took over the family enterprises with the help of her two sons.

“Rumor had it that old lady Bernstein didn’t care if anybody was out there and didn’t want the island developed,” said Cliff Hartman, a palm-frond weaver who once lived on the island. “She wanted it to be a sanctuary for hermit crabs and butterflies.”

Not so, said Roger Bernstein; over the years, the family entertained ideas for a campground and other projects, but none seemed right.

Miriam Bernstein died in 2004, and three years later Roger Bernstein presented a development plan to Monroe County for 35 vacation homes, 35 rental cottages with 85 bedrooms, five workforce houses, a bar, restaurant, retail store and boat moorings.

The Bernsteins fought the island’s residential-conservation zoning, which allows only one house per 10 acres.

“It’s not a pristine tropical island; there’s garbage trees on there and garbage bushes,” Roger Bernstein said. (The invasive Australian pines that dominate the landscape, along with Brazilian peppers, led to its nickname, Christmas Tree Island.)

Bernstein argued that the island had become an illegal dump and a haven for criminals. Last year, he hired 17 workers to haul away the tons of garbage and debris. The cleanup took three weeks, and required more than 100 boat trips.

“You wouldn’t believe the stuff we got off that island,” said Jim Vernon, who helped. The list included a gorilla mask, a rusted knight-in-shining-armor outfit, musical instruments and a vacuum cleaner.

The Bernsteins’ F.E.B. Corp. filed suit against the United States in August, arguing that the federal government ceded ownership of the submerged bay bottom on which the island was later built when Florida was admitted to the Union in 1845. Even the U.S. Navy thought the Bernsteins owned the island in 2005 and 2006, their lawyers say, when it entered into license agreements to use the property for Navy SEAL training.