From a distance the subtropical keys appear as a string of emeralds rising from azure waters along the edge of Biscayne Bay. Together the islands shelter the bay as well as the Florida mainland, from the ocean.
Elliott Key, often considered the first of the Florida Keys, is the largest island in the park. Its foundation, composed of ancient coral reefs, was formed when the ocean was much higher than it is now. A closer look at the stone reveals the types of corals in the composition.
The islands north of Elliott, including Sands and Soldier Keys, share features of the hard rock coral keys to the south and other features with the sand barrier islands to the north.
Salt tolerant plants thrive along island shorelines. They include mangroves, saltwort, glasswort and sea purslane. Moving inland, the plants change to mahogany, paradise tree, gumbo limbo, satinleaf and ironwood. These tropical trees are not found in the continental United States outside of South Florida.
Insects are noticed at once. Dragonflies feed on mosquitoes. Butterflies, including the endangered Schaus' swallowtail, flutter from tree to tree. Spiders weave their golden orbs in hope of catching their next meal. Hundreds of other insects make these tropical keys their homes.
Lizards, raccoons, snakes, marsh rabbits and mice weave through the underbrush.
Cultural resources are plenitful. The Tequesta established hunting and fishing camps on the islands. Pioneers farmed, fished and salvaged ships that foundered on nearby coral reefs. Wealthy visitors built retreats on Boca Chita Key and Adams Key.
These mostly undeveloped Florida Keys provide glimpses of the days before the arrival of machinery and industry. They provide places for relaxation and recreation, and serve as stepping stones to adjacent coral reefs.