Deadwood officials leading effort to legalize sports betting in South Dakota Tom Griffith, West Central Tribune · December 7, 2018 at 3:26 pm The South Dakota Legislature in January will be asked to pave the way for legalized sports betting in the state. Proponents pushing a constitutional amendment to allow the gaming in Deadwood casinos want lawmakers to place the question on the 2020 ballot. Several states now offer sports betting and others are considering it following a U.S. Supreme Court ruling in May. The decision struck down a federal law which banned such betting outside of Nevada. The ruling allows individual states to determine if sports betting will be allowed.