MaryAnn Dennis, 88, of Riverton passed away on Monday, December 7, 2020 at Wyoming Medical Center in Casper, WY. A rosary will be recited at 7:00 pm on Monday, December 14, 2020 at St. Margaret’s Catholic Church. A memorial service will be at 10:00 am on Tuesday, December 15, 2020 at St. Margaret’s Catholic Church.