Leadville is the statutory city that is the county seat and only incorporated municipality in Lake County, Colorado, United States. The city population was 2,602 at the 2010 United States Census. Situated at an elevation of , Leadville is the highest incorporated city and the second highest incorporated municipality in the United States. A former silver mining town that lies near the headwaters of the Arkansas River in the heart of the Rocky Mountains, the Leadville Historic District contains many historic structures and sites from its dynamic mining era. In the late 19th century, Leadville was the second most populous city in Colorado, after Denver.