Daily Overview on Instagram: "The Black Thunder Coal Mine in Gillette, Wyoming, USA, opened in 1977 and has grown to become one of the largest coal mines in the world. Massive dragline excavators — the largest of which holds 160 cubic yards (120 cubic meters) in a single bucket — strip away the earth’s surface to extract coal deposits below. Now covering roughly 200 square miles (518 sq. km), Black Thunder provides the US with 8% of its coal supply. Created by @dailyoverview Source imagery: NASA

World's Largest Coal Mine