Sky Islands are forested mountain ranges (generally above 5,000 feet in elevation) that are isolated from each other by intervening basins and valleys of desert and grassland (usually below 4,000 feet in elevation).

A landscape of wonder, beauty, and wildness, these mountains are among the most diverse ecosystems in North America due to their great topographic relief and location at the meeting point of major desert and forest biomes.

The southwestern Sky Island “archipelago” is the only Sky Island complex extending from subtropical to temperate latitudes with a globally unprecedented array of plant and animal species of northern and southern origins. Many tropical and subtropical species inhabit this region—jaguar, coatimundi, Mexican long-tongued bat, elegant trogon, violet-crowned hummingbird, and banded rock rattlesnake. Eighteen species of bats, 400+ species of birds, and about 100 species of butterflies can be seen here. Herds of the rare, desert bighorn sheep survive in the most rugged and remote terrain. This is also one of the few places in the world where the saguaro cactus grows.

The Santa Cruz Valley is the only place in the United States where tourists can visit the sky islands and desert seas landscape and enjoy the exceptional scenic views and biological complexity in a National Heritage Area. Learn more about the Sky Islands and Desert Seas here.