The only human residents are park rangers. Unfortunately, their electric generator can be quite loud at night. The rangers run a tram from the dock across the island to the gulf, where there are picnic tables, campsites and rustic cabins with common bathrooms and running water, but no electricity. Hiking trails also are part of the park. Cayo Costa and Punta Blanca are bird sanctuaries, harboring, among others, magnificent frigate birds, ospreys and bald eagles.
Vegetation is lush.
One, Murdock Bayou, leads to a watery tunnel through the mangroves that cuts the island nearly in two and empties onto the back side of a gulf beach.