McAllen is a city in Hialgo County, Texas. It is located at the very southern tip of Texas in an area known as the Rio Grande Valley. As of 2005, the city had a population of 126,411. In 2005, the McAllen–Edinburg–Mission Metropolitan Statistical Area had a population of 700,634. It is the 187th largest city in the U.S. and the 71st largest metropolitan area. Its southern boundary is located about five miles from the U.S.-Mexico border, the Rio Grande River and about 70 miles west of South Padre Island and the Gulf of Mexico. McAllen is one of the fastest growing cities in the country. It is also the largest city in Hidalgo County.