The Kansas City metropolitan area is a bi-state metropolitan area anchored by Kansas City, Missouri. Its 14 counties straddle the border between the U.S. states of Missouri (9 counties) and Kansas (5 counties). With 8,472 square miles (21,940 km2) and a population of more than 2.2 million people, it is the second-largest metropolitan area centered in Missouri (after Greater St. Louis) and is the largest metropolitan area in Kansas, though Wichita is the largest metropolitan area centered in Kansas. Alongside Kansas City, Missouri, these are the suburbs with populations above 100,000: Overland Park, Kansas; Kansas City, Kansas; Olathe, Kansas; Independence, Missouri; and Lee's Summit, Missouri.
Huanglong County, which belongs to Yan'an City, Shaanxi Province, is located in the hilly and gully region of the Loess Plateau, in the north-central part of Shaanxi Province, on the southeast edge of Yan'an City. It is bordered by Luochuan in the west, Baishui in the south, Chengcheng and Heyang in the south, Hancheng in the east and Yichuan in the north. It is located between latitude 35 °24 °05 north latitude and longitude 110 °16 °49 east longitude, between north and south longitude 69.754 km long, east-west width 62.195 km, and total area 2752 square km. The skull fossils of the "Huanglong Man" unearthed about 50,000 years ago in Huanglong County filled a missing ring in the history of human development in China, and discovered the largest giant stone stone in the Neolithic Age in China.