Marking the east edge of the Salt River Valley, the Superstition Mountains are a highly visible landmark. The name of the mountains comes from the stories of Indian gold and lost mines associated with the range. The Salt River Valley is home to Phoenix, Mesa, Scottsdale, Tempe, Chandler, Gilbert, Glendale, Peoria, Surprise, Goodyear, and many other large and small communities. Phoenix is the sixth largest city in the United States by population. The highest point of the mountain range is not visible from the valley, but the peaks with their impressive cliffs are over 4000 feet high. The area around the mountains is a designated wilderness and all vehicular traffic is excluded. Temperatures in the summer months climb to well over 115 degrees Fahrenheit. There are a number of trails for hiking and horse back riding in the Wilderness and despite its proximity to a large metropolitan area, it is a rugged and difficult place to visit.