Monarch is an unincorporated community in Sheridan County, Wyoming, United States. Monarch is located along Interstate 90, 8.3 miles (13.4 km) north-northwest of Sheridan. It was founded in 1903 as one of many coal company towns in the area. It was all but abandoned in 1953.[2] Monarch is 3,650 feet (1,113 m) above sea level. Monarch area code (307).