Display 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." Many vestiges of those days remain in pockets throughout what is now a city of about 35,000 people, whose Uptown Historic District alone contains more than 6,000 properties listed on the National Register of Historic Places. Photo by Carol Highsmith, 2022.