Mesa is a city in Maricopa County, in the U.S. state of Arizona and is a suburb located about 20 miles east of Phoenix. Mesa is in the East Valley section of the Phoenix Metropolitan Area. It is bordered by Tempe on the west, the Salt River Pima-Maricopa Indian Community on the north, Chandler and Gilbert on the south, and Apache Junction on the east. Mesa is the third-largest city in Arizona, after Phoenix and Tucson, and the 38th-largest city in the country. Despite being home to more than 460,000 people, making its population larger than more recognizable cities such as Miami, St. Louis and Oakland, Mesa is decidedly a bedroom community. Mesa is home to the Polytechnic campus of Arizona State University.