Almost two dozen separate mountain ranges jut out of the desert floor across southeastern Arizona creating different micro-ecosystems that are referred to as "Sky Islands".

"Some of the mountains rise more than 6,000 feet above the surrounding desert floor making the lowlands and high peaks drastically different. Plants and animals living in the mountains could never survive in the surrounding deserts. Thus by analogy, the mountains are “islands” surrounded by deserts that are “seas”.

The Sky Islands connect two very different mountainous regions, the subtropical Sierra Madre of Mexico and the temperate Rocky Mountains of the United States. The mixing of these southern and northern biotas is truly (a) unique (Southwest Vibe)."