Post Offices in Riverton, Wyoming, United States SearchSearch SearchSearch View: Grid 1View: Grid 2View: Grid 3View: Grid 4View: Grid 5View: List Riverton Post Office No Reviews Favorite Fax: (307) 856-9033Phone: (307) 856-3725Retail Hours Riverton Annex Post Office No Reviews Favorite Fax: (307) 856-0518Phone: (307) 857-0127Retail Hours