Colorado Springs is a home rule municipality in, and the county seat of, El Paso County, Colorado, United States. It is the largest city in El Paso County, with a population of 478,961 at the 2020 United States Census, a 15.02% increase since 2010. Colorado Springs is the second-most populous city and the most extensive city in the state of Colorado, and the 40th-most populous city in the United States. It is the principal city of the Colorado Springs metropolitan area and the second-most prominent city of the Front Range Urban Corridor. It is located in east-central Colorado, on Fountain Creek, 70 miles (113 km) south of Denver.
Mianning County, which belongs to Liangshan Yi Autonomous Prefecture of Sichuan Province, is located in the southwest of Sichuan Province, in the north of Liangshan Yi Autonomous Prefecture, adjacent to Xiaoxiangling in the east, Xichang and Yanyuan in the south, Muli and Jiulong in the west, and Bodhisattva Gang and Shimian County in the north. The total area is 4420 square kilometers. Mianning is located in the Panxi Rift Valley, and the Anning River and Nanya River originate in the territory. The Yalong River winds through the southwest and is known as the rice granary on the banks of the Anning River. It is a "major county of national grain production" and "a big county for pig transfer". More than 30 kinds of minerals have been proved to be of mining value, among which the reserves of rare earths rank second in the country. Mianning is an old revolutionary base. In 24 (1935), after the long March of the Red Army passed through Mianning, the Red Army was established to enter Sichuan.