The historic Orphan Girl Mine entrance that in 1965 became the first site at the World Museum of Mining in Butte, Montana, a thriving late 1800s and early 1900s gold, silver, and copper mining boomtown — so prosperous that it was known as "The Richest Hill on Earth." It is now a city of about 35,000 population whose Uptown Historic District alone contains more than 6,000 properties listed on the National Register of Historic Places. Photo by Carol Highsmith, 2022.