Team Logo. The Sioux City Explorers are a team in the American Association. They were one of the charter members of the league. They are sometimes called "The X's". Retrieved from "https://prosportsteams.fandom.com/wiki/Sioux_City_Explorers?oldid=17598" Categories: American Association Teams Northern League Teams Teams in Iowa Teams in Sioux City Community content is available under CC-BY-SA unless otherwise noted.