High Cienega, Mt. GrahamThere are at least 18 plants and animals unique to the world that have evolved on Mt. Graham's Galapagos-like, "sky island" Hudsonian forest summit ecosystem. These include three mammals, three flowering species, three unique mollusks and many arthropods (see below). They are adapted for survival to subzero boreal forest winters. Many other species on Mt. Graham remain to be identified.