 It has a sky island character, with dense coniferous forests at the higher elevations.The longer, narrow northern portion is lower, reaching only 7,310 ft (2,228 m) at Gillespie Peak, and is characterized by grassland and piñon-juniper woods and shrubs.The Animas Mountains lie near the Chihuahuan Desert, the Sonoran Desert, the Sierra Madre Occidental of Mexico, and the mountains surrounding the headwaters of the Gila River.