Some of the best remaining examples of native Illinois ecosystems are right here in the Forest Preserves of Cook County. About 55,000 acres of Cook County’s 68,000 acres of preserves are in a natural state. Unfortunately 68% of those are in ecologically poor condition. Every weekend, in all parts of the county, teams of dedicated volunteers enjoy the company of other eco-minded people while saving the flora and fauna of some of the best natural areas in the state. Join us for a Work Day Event.