Brush Shrouds Burial Mounds.

Byline: Baird Helgeson

Sep. 16--COCKROACH BAY -- Lewis F. Symmes III doesn't consider himself a rich man, but he does have an island.

Symmes and his family have irritated government officials for three generations by refusing to sell their undeveloped island deep in the Cockroach Bay Aquatic Preserve in southern Hillsborough County.

There is no bridge to the tiny outpost about 100 yards from shore in the 8,583-acre preserve.

The myths surrounding the island called Big Cockroach Mound are legend in these parts. Symmes is a bit of a mystery himself. Local lore has it that Symmes is a recluse, perhaps nearing 100, who relies on friends to check on his island. A couple of anglers said they heard that a governor gave him the island as a favor.

In truth, the man locals call "Old Man Symmes" is the third generation of Symmeses to own the land. The man said to be a curmudgeonly hermit is a chatty retired quality-control engineer for TRW Inc.'s Delta and Atlas space programs.

The island was once part of a failed get-rich-quick plan concocted by Symmes' grandfather. Then there are the stories of buried pirate treasure.

In reality, Big Cockroach Mound is a 10-acre isle of seashells covered by dense, thorny brush, mangroves and gumbo limbo trees. The island is home to three American Indian burial mounds, making it the most archaeologically significant land in the preserve. Artifacts are so significant that workers with the Smithsonian Institute once traveled here to produce a map of the island and its contents.

The harsh wilderness allows Eastern indigo snakes and black-and-yellow garden spiders to thrive. The matchbook-size spiders weave glistening tapestries of webs…