Horn Island, Gulf Islands National Seashore Professional Review and Guide
"Horn Island is approximately 14 miles long and is estimated at 3,535 acres by the National Park Service. It features the most varied terrain of the two wilderness islands and the best hiking. Cross trails are maintained at either end of the island; crossing near the center, where the island is 1 mile wide, is possible at a trail near the old chimney, the only one on the island. Otherwise crossing at the island’s center can be difficult due to a dense patchwork of vegetation, pine forests, and numerous lagoons.
Ponds on the island include Long Pond on the east tip, Garden and Water’s Pond, and Middle Ponds. Various stickers and cactus spines, and the fact that summer heat makes the sand hot enough to burn bare feet, makes shoes a necessity when hiking here. One of the more interesting plants you might observe is the dodder, a vine that grows over other trees and bushes. It derives its energy from the host plant, and because it is not involved in photosynthesis, it does not produce chlorophyll—its color will be a yellow-orange all year-round."