Tonopah is a census-designated place in western Maricopa County, Arizona, United States, approximately 50 miles west of downtown Phoenix off Interstate 10. The community is near the Palo Verde Nuclear Generating Station, the largest power producer in the country, nuclear or otherwise.
Local legend says that the name Tonopah derives from the word Tú Nohwá, meaning "Hot Water Under a Bush". Others say it got its name from the Tonopah/Belmont Mine which was owned by a Tonopah, Nevada, operation. It is located on the Tonopah Desert. Many wells in Tonopah are warm, in the 70 to 95 degrees F range and many are hot; 110 to 120° F wells are common. Prior to being called Tonopah, the settlement was known as Lone Peak.
The area is also known to have been inhabited by groups of people for resource gathering area of the Hohokom, Patayan and Yavapai.