Sky Island - Origin of The Term

Origin of The Term

The term was popularized by nature writer Weldon Heald, a resident of southeastern Arizona. In his 1967 book, Sky Island, he demonstrated the concept by describing a drive from the town of Rodeo, New Mexico, in the western Chihuahuan desert, to a peak in the Chiricahua Mountains, 35 mi (56 km) away and 5,600 ft (1,707 m) higher in elevation. Ascending from the hot, arid desert, the environment transitions to grassland, then to oak-pine woodland, pine forest, and finally to spruce-fir-aspen forest. The book mentions the concept of biome, but prefers the terminology of life zones, and makes reference to the work of Clinton Hart Merriam. The book also describes the wildlife and living conditions of the Chiricahuas.

Around the same time, the idea of mountains as islands of habitat took hold with scientists and has been used by such popular writers as David Quammen and John McPhee. This concept falls within the study of island biogeography. It is not limited to mountains in southwestern North America but can be applied to mountains, highlands, and massifs around the world.

Much earlier, the sky island concept was mentioned in 1943 by Natt N. Dodge in an article in Arizona Highways magazine when he referred to the Chiricahua Mountains in southeastern Arizona as a ". . . mountain island in a desert sea".