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.
Yanchang County, which belongs to Yan'an City, Shaanxi Province, is located in the north of Shaanxi Province and east of Yan'an City. It is 73 kilometers from east to west and 55 kilometers from north to south, with a total area of 2368.7 square kilometers. The early human activities in Yanchang County can be traced back to the Neolithic Age. Western Jin Tai began two years (266 years), established the establishment of the county. Several changes, to the second year of Tang Guangde (764), because the Yanhe River from the county from west to east into the Yellow River, the name Yanchang County, still in use. The terrain tilts from northwest to southeast, high in the north and south, low in the middle, showing a valley peak type. Is a warm temperate dry continental monsoon climate, spring, summer, autumn and winter four distinct seasons, cold, warm, dry and wet. By 2018, Yanchang County had jurisdiction over one street and seven towns with a resident population of 128500, achieving a GDP of 54.077.