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.
The name Tonopah derives from the word Tú Nohwá, meaning "Hot Water Under a Bush", referring to its location on the Tonopah Desert, underneath which there is an extensive subterranean aquifer so that wells dug in the area never lack water. Some agricultural wells pump at the rate of 2,500 gallons per minute for days at a time. Many wells in Tonopah are warm, in the 70 to 95 degree 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 the Yavapai.