Denton is located on the north end of the Dallas–Fort Worth metroplex in North Texas with over 113,000 residents. These three cities form the area known as the Golden Triangle of North Texas. Part of the city is located atop the Barnett Shale which is a geological formation believed to contain large quantities of natural gas. Lewisville Lake, a man-made reservoir, is located 15 miles south of the city. With over 45,000 students enrolled at the two universities located within its city limits, Denton is often characterized as a college town.