A Boulder and Weld County Home Rule Municipality, Longmont is located 33 miles north-northwest of Denver. Named after the mountain, Longs Peak, from the explorer Stephen H. Long, Longmont is the 13th most populated city in the state of Colorado. Founded in 1871 by people from Chicago, it was earlier called the Chicago-Colorado Colony. Development started in the agriculture driven community only after the building of the Colorado Central Railroad. The city gained recognition in the 1960s when agriculture waned and multinationals, such as IBM, Seagate, and Amgen, shifted based here. U.S. Highway 287 passes through the center of the city. A tributary of South Platte River, St. Vrain Creek, flows just south of the city center.