The mission of the Illinois Department of Natural Resources is to manage, protect and sustain Illinois' natural and cultural resources; provide resource-compatible recreational opportunites; and promote natural resource-related public safety, education, and science.

The Department provides many of the State's outdoor recreational opportunities (state parks and museums): ensures that desirable fish and wildlife species are available in sufficient numbers to permit public fishing and hunting; performs basic and applied research; maintains extensive collections; publishes scientific reports and articles; permits mining, oil and gas operation; enforces various acts that govern oil, gas and mining; reclaims lands and waters adversely affected by mining; constructs and regulates state water resource programs.