Red Lodge is a city and county seat of Carbon County, Montana, United States. As of the 2020 census, the population of the city was 2,257. …Red Lodge is a city and county seat of Carbon County, Montana, United States. As of the 2020 census, the population of the city was 2,257. On September 17, 1851, the United States government signed a treaty with the Crow Nation, confirming control of the area which now contains Red Lodge, MT to the Crow Indians. Rich coal deposits were found there in 1866, and gold was discovered nearby in 1870. An 1880 treaty between the U.S. government and the Crow allowed the area to be settled starting April 11, 1882.