The island, in part, shelters and bounds the Mississippi Sound to its north, and has a long beach on the Gulf of Mexico on its south side.

It is home to varied wildlife including alligators, ospreys, pelicans, anhingas, ibises, manatees, ducks, rabbits, raccoons, tern, herons, and other migratory birds.

[2] Horn-island is very flat and tolerably wooded, about six leagues in length, narrowed to a point to the west side.

These cattle not requiring any attendance, or other care, in this island, came to multiply in such a manner, that the owners made great profits of them on our arrival in the colony.

From 1943 to 1945, Horn Island was closed to all public access and activity for use as a biological weapons testing site by the U.S.