The Sierra Estrella (, , ) is a mountain range located southwest of Phoenix, Arizona. Much of the range falls within the Gila River Indian Reservation, but of BLM land is protected as the Sierra Estrella Wilderness. Description On the highest peaks, temperatures are usually 8–12 degrees (Fahrenheit) cooler than in the valley. Snow can be seen at least once or twice a year on the highest points of the mountain range (typically above 4,000 ft). Sometimes, the snow level can drop near , but depends if the precipitation reaches the mountain range. A good example is during the month of March 2006, when a heavy storm system reached the state and lowered snow levels near . Once the skies cleared next morning, snow covered the Estrella's mountain tops. Estrella Mountain Regional park occupies in the northern portion of the range. The park offers multi-use trails including a competitive loop for running and mountain biking. Equestrian use is permitted. The park has parking and a riding arena. History The Sierra Estrellas were inhabited by the Akimel O'odham people and also some Yavapai bands at the north end of the range at the time of Spanish colonization, and today the mountains tower over several of the Akimel O'odham and Maricopa villages of the Gila River Indian Community. There are petroglyphs throughout the Southern portion of the range. In the colonial era, they were part of the land claimed as New Spain. Occasionally Spanish explorers or priests, most notably Father Kino, would venture near the range to document the area and contact the Akimel O'odham. On his return from the Colorado River in March 1699, Kino climbed a pass through the Sierra Estrellas and saw the Río Salado and Río Verde that he drew on his maps. In 1810, Mexico declared independence from Spain, and the Sierra Estrellas went on to become part of Mexico. In 1827, a French fur trapping expedition led by Michel Robidoux was attacked by Indians and survivors escaped into the Sierra Estrella mountains. In 1853, the United States acquired the Estrellas from Mexico as part of the Gadsden purchase. It soon became part of a trade route for settlers in California known as the Butterfield Overland stage. People and equipment could be moved across the area much quicker. The route was massively successful in its time, moving millions of dollars in supplies. However, it was short-lived. Steam