About the Sky Islands

Southwestern New Mexico, southeastern Arizona, northwestern Chihuahua, and northeastern Sonora are a landscape of wonder, beauty, wildness, and mind-boggling biological diversity. Aldo Leopold saw this landscape as a single ecological region, as we do today.

"To my mind these live oak-dotted hills fat with side oats grama, these pine-clad mesas spangled with flowers, these lazy trout streams burbling along under great sycamores and cottonwoods, come near to being the cream of creation." So wrote Aldo Leopold in 1937.

This landscape that so enthralled Leopold was where the Rocky Mountains and the Sierra Madre kiss, where the plants and animals of the Neotropics mingle with those of the Nearctic, where jaguar and grizzly hunted the same ridges, where elk and javelina browsed and rooted cheek to jowl, where northern goshawks took thick-billed parrots on the wing.

Weldon Heald used the term "sky islands" in 1967 to denote mountain ranges that are isolated from each other by intervening valleys of grassland or desert. The valleys of this basin-and-range country act as barriers to the movement of woodland and forest species somewhat as saltwater seas isolate plants and animals on oceanic islands. The 40 ranges of the Sky Island system may be thought of as an archipelago.

The greater Sky Islands Region is globally important for the lessons it taught Leopold, for its role in launching the wilderness preservation movement, and for its wild and enchanting landscape. We now understand, as he did many decades ago, that the region is also of international importance because of its outstanding biological diversity.

Click here for “An Ecological Analysis of Conservation Priorities in the Apache Highlands Ecoregion (PDF).”

Click here to read Peter Warshall's overview of the Sky Island Region.

Browse the Sky Island Library

Public Lands:

The Sky Island Region is rich in lands managed by government agencies: the U.S. Forest Service, the U.S. Bureau of Land Management, the U.S. Fish and Wildlife Service, the U.S. Park Service, State Game and Fish Departments, the Mexican Federal Government, the States of Sonora and Chihuahua, and others. Conservation on these government-managed lands is essential to the future ecological and economic health of the region.

Want to know more about the Sky Islands' public lands? Click here.

Private Stakeholders:

Anyone who benefits from the ecological wealth of the Sky Island Region is a stakeholder in conservation. Private-sector stakeholders—whether individual citizens or local and regional organizations—can tip the balance in favor of long-term resilience, on public lands or private.

Are you a stakeholder? Click here.