As of the census of 2000, there were 678 people, 277 households, and 186 families residing in the town. The population density was 1,429.1 people per square mile (557.0Square kilometers). There were 304 housing units at an average density of 640.8 per square mile (249.7Square kilometers). Dayton is located at the confluence of the Tongue River and The Little Tongue River. It is on US Highway 14, just east of the Big Horn Mountains. Dayton is a town in Sheridan County, Wyoming, United States. The population was 678 at the 2000 census.