Union Reservoir is an artificial reservoir located southeast of the intersection of Smartville Road and Highway 20 in Smartsville. It is formed by a dam 700 feet long, 30 feet deep in the middle, 5 feet wide on top, and 100 feet wide at the bottom.1 The dam is lined with a riprap stone wall.
- 1Statistics of Mines and Mining in the States and Territories West of the Rocky Mountains: Seventh Annual Report by Rossiter Worthington Raymond. Washington, D.C.: Government Printing Office, 1875
