It depends on whether you turn left or you turn right, but either way, you are driving right up to a fascinating, yet obscure, historic site. I’m talking about Exit 190 of Interstate 94, the Driscoll Exit. If you go north, you come to the neglected state historic site, Camp Banks, with its decrepit monument to Chaska, the Dakota scout. The scout served with the Sibley Expedition of 1863 and was poisoned by the soldiers, who mistakenly believed Chaska had played some part in the killing of one of