You have found a sycamore tree. The sycamore is not truly a prairie species. It makes inroads into the Great Plains along the river valleys of the eastern part of the area from Nebraska on south. It is a boundary marker in the ongoing struggle between the tallgrass prairie and eastern deciduous forest biomes. Prolonged wet cycles allow the trees to move west.
Dry years favor the grasses.
In the river valleys the trees always get an edge because of the extra moisture that is present, so the woodlands extend out onto the plains in slender fingers of riparian forest. Indeed, the sycamore prefers deep river-bottom soils. Individual trees may live over 500 years. The leaves of the sycamore are very large, just like the tree. They have numerous short hairs on the stem and veins, giving them a fuzzy feel.