Kwimlilthia Slough is a gut located in Kusilvak County, Alaska. It appears on the Kwiguk C-5 NE USGS 7.5-minute topographic quadrangle. The elevation at this location is approximately 15.03 feet (4.58 m) above sea level. The nearest populated place is Trogshak (historical), approximately 4.5 miles to the WNW.