Rathbun Irrigation Number 1 Reservoir is a reservoir located in Hot Springs County, Wyoming. It appears on the Rathbun Ranch USGS 7.5-minute topographic quadrangle. The elevation at this location is approximately 6,115.52 feet (1,864.01 m) above sea level. The nearest populated place is Nickelson Place, approximately 11.2 miles to the W.