The Westvaco Mine is located in the Green River Basin of Sweetwater County, Wyoming, one of the world's premier trona-producing regions. Westvaco operates a longwall mine and currently produces approximately 3.5 million short tons per year (3.2 mmtpa) of soda ash, with a target to increase production by an additional 1.1–1.7 Mtpa in the near term by both the optimization of the existing facilities and the staged expansion using solution mining.