Argosy Casino. Argosy Casino Sioux City was a riverboat casino located on the Missouri River in Sioux City, Iowa. 28 likes · were here. Reviews from Argosy Casino employees about Argosy Casino culture, salaries, benefits, work-life balance, management, job security, and more. Directions. Court St. +1 () ; Website. You can't even. Previously, the. Argosy Casino Sioux City Website ; Casino. The former Argosy Sioux City casino has been sold to an Illinois firm that hopes to move the riverboat down the Missouri River as early as next. It was a riverboat casino that has been closed for quite a while. Don't plan a trip to Sioux City with the idea you will gamble at the Argosy. () More. Advertisement. The former Argosy riverboat casino has pulled away from its dock in Sioux City and started its journey to a shipyard in Illinois. Sioux City, IA () Also at this address. Landmark & Historical Place. . It was an abrupt end to an operation that began in when the Argosy opened on Sioux City's riverfront to great fanfare. Argosy Casino Sioux City ; Address. It was owned by Penn National Gaming. Larsen Park Rd Sioux City IA USA ; Telephone. Argosy Casino, Sioux City, IA.