The Great Western Prairie http://www.epd.org/parks/elmhurst-great-western-prairie.asp in Elmhurst is an original prairie remnant that was left alone because it was between the Chicago Great Western Railway and the Chicago Aurora & Elgin railroad - now the IL Prairie Path. It has been watched over and maintained with the support of the Elmhurst Park District and many volunteers. Keith Olson is the prairie maintenance coordinator and helps the volunteers while letting you know about the different plants.
Here is the information about their schedule for volunteers:

Dear Prairie Restoration Volunteers:
Plan for the scheduled August workday:

Where: In Elmhurst at Berkley Ave. and the Illinois Prairie Path
When: Saturday, August 18 at 9 A.M. (third Saturday)
What: Clearing brush - several types
Weeding - several kinds
Other projects as needed (seed gathering?)

Bring: Work gloves; wear work clothes and sturdy shoes.
Questions? David Price at dprice@epd.org or 630-993-8909
or Keith Olson at keitholson@usa.net or 630-834-7357
Looking ahead, mark Sept. 15 and Oct. 20_________________________________________________
When you are in Elmhurst or on the IL Prairie Path stop and enjoy the prairie. When you have the time try to volunteer and help the prairie.