Rock Springs Conservation Area is a 1,300 acre (5 km2) park located 4 miles (6.5 km) southwest of Decatur, Illinois.
Rock Spring is a natural outflow of water from the sandstone bluffs on the south bank of the Sangamon River.
The area surrounding the springs consists of Sangamon River wetlands and low bluffs of marginal agricultural productivity.
As the population of Decatur grew sharply in the early 20th century, large parcels of land alongside the Sangamon were condemned so that the metropolis could build a modern sewage plant.
The current Rock Springs Conservation Area and Nature Center are the products of this urban-planning initiative.