Great singletrack with several challenging climbs and varying degrees of technical difficulty. It is well maintained and fun. Just follow the yellow trail and you can't get lost.
How to get there:
Rt. 29 out of Peoria towards Pekin. Left on Rt. 98, up the hill and on the opposite side of McNaughton Park Rd. and McNaughton Pk. There is a parking lot and from there just ridge across the open field to the Dirksen Trail sign.
Also a good trail in McNaughton Park to ride