The Leadville Historic District is in the mining town of Leadville, Colorado. The National Historic Landmark District includes 67 mines in the mining district east of the city up to the 12,000 foot level, and a defined portion of the village area. It was designated in 1961. Then, when the National Register of Historic Places (NRHP) program was started in 1966, Leadville's National Historic District was included in its first day's listings, along with all other existing National Historic Landmarks. The NRHP district was later expanded, adding a number of structures along the Harrison Avenue corridor, and making them eligible for historic preservation grants and tax subsidies, too.