Weldon Springs State Recreation Area - Geology and Ecology

Geology and Ecology

Weldon Springs is an unusual spring in the relatively flat Grande Prairie of central Illinois. The spring is a local reminder of the former presence of an immense buried river valley, the Teays River, once as large as the Mississippi River. Glacial till left behind during the Ice Age buried the valley and its bedrock bluffs below the current earth surface, but much later flows of groundwater were forced by this buried geological feature to the surface. Weldon Springs became a wetland with some of the northernmost bald cypress trees in Illinois.