The Kalahari-Oranje Museum is the right first stop in Upington. It occupies the old Olyvenhoutsdrift mission station, the settlement that grew into the modern town, and covers the river, farming, local settlement, and the dry-country life around the lower Orange.
Outside, look for the donkey statue. It is a small but telling monument to the animals that once pumped water and hauled loads in a place where every practical job mattered.