Ranches in Sheridan County accessed coal outcrops with pick and shovel as early as 1880, and these "wagon mines," named because people loaded the coal directly into wagons, supplied heat and cooking fuel for local homes and businesses. Full-scale development followed the arrival of the Burlington and Missouri Railroad, part of the Chicago, Burlington and Quincy Railroad, in 1892, when the railroad used the coal and hauled it to distant markets. The capital and labor for large mines came from outside the region, and more than 20 nationalities were eventually represented in the Sheridan County coal mines. Demand from industrialization created a boom in the 1890s, wartime demand brought further booms during World War I and World War II, coal prices crashed in 1921 as natural gas replaced coal, and after 1945 a decades-long decline began as locomotives switched to diesel fuel and natural gas and oil continued to replace coal. In 1953 the last underground mine in Sheridan County closed and the first open pit mine opened, and in the 1970s coal boomed again with the oil embargo and continued through 1012 as Powder River Basin coal helped fuel the world.