Also known as Mount Graham, this is the tallest of the Madrean Sky Islands reaching 10,720 feet. It is the only Sky Island with a true spruce/fir forest community. The Pinaleños have many species including the Mt. Graham red squirrel and Alnus incana ssp. tenuifolia, which reveal its affinity to the high country of the Rocky Mountains. It is still well within the realm of Madrean influence as well, with well-formed Madrean oak woodland on much of its lower slopes.
A young Mount Graham red squirrel, which was staying very still, perhaps attempting to prevent detection.
The old growth forest on Mt. Graham (Pinaleno Mountains) of eastern Arizona is comprised of forest patches rather than being homogeneous in composition. These patches reflect the heterogeneity of disturbances that occur on the mountain. The two primary disturbances have been fire and wind, although clearing for road construction and recently for an astronomical observatory also are important. The forest patches represent different stages in forest succession following disturbance. Patches can be described as open, forest edge, and mature and old growth forest.
