Mr. Stotts and Mr. Edleman founded the Monarch Mine in 1903, and L.H. Brooks, William C. Ervine, and J.B. Kendrick, later a Wyoming U.S. senator and governor, later consolidated it. Mining began to decline in the early 1920s, and by the 1930s a small amount of coal still mined in the area was primarily for local use. Monarch was formally abandoned in 1953, and all that remains today are a few livestock structures, the town water tower, St. Thomas Catholic Church, and the mine foreman's house. Mining was dangerous in all its aspects. Miners dug tunnels into the coal vein and opened individual rooms at right angles off the main tunnel, working in pairs as one miner undercut the wall of coal with his pick while the second loaded coal into a coal car, then blasting the face and removing the fallen coal. From 1911 to 1926, the height of mining in the Sheridan area, approximately 659 miners died in Wyoming from mine explosions, inhalation of toxic gases, and crushing by mine collapse and coal car. In one of the worst accidents in the region, two miners died in an explosion in Dietz Mine No. 8 on June 4, 1919; one of them, Bob Gault, had traded his usual shift with another miner so he could attend his daughter's wedding the next day. Wyoming Territory's 1886 Coal Mine Safety Act made it a leader in improving mining conditions by implementing safety codes and prohibiting boys under 14 and all females from being in or around the mines.