Weldon Springs State Park in central Illinois preserves an unusual spring and wetland landscape shaped by the buried valley of the ancient Teays River, whose hidden course still directs groundwater to the surface. The area became notable for supporting some of the northernmost bald cypress trees in Illinois. In the late 19th and early 20th centuries, springs once used by Judge Lawrence Weldon’s fishing camp were transformed into a major Chautauqua destination, attracting prominent national speakers and performers until that movement declined. Later donated and brought into state ownership, the park now combines recreation, habitat conservation, historic preservation, and a separate Piatt County unit along the Sangamon River.