Fountain Hills is a town in Maricopa County, Arizona, USA, neighboring the Fort McDowell Yavapai Nation, Salt River Pima-Maricopa Indian Community and Scottsdale, AZ. The population is 24,669, as of the 2006 Census. It was the eighth fastest-growing place among cities and towns in Arizona between the 1990 and 2000 census. It has the world's fourth tallest fountain. Charles W. Juels' Fountain Hills Observatory is nearby. The town has two annual fairs, a local art fair and the Fountain Hills Great Fair which incorporates arts and a carnival. The town has the only Thanksgiving Day parade west of the Mississippi River.