Question: when did the wsop move to the rio
Answer: In 2004 , Harrah 's Entertainment ( now Caesars Entertainment ) purchased Binion 's Horseshoe , retained the rights to the Horseshoe and World Series of Poker brands , sold the hotel and casino to MTR Gaming Group , and announced that the 2005 Series events would be held at the Harrah 's - owned Rio Hotel and Casino , located just off the Las Vegas Strip .