it's on mehaffey bridge road... my bad, just did a map quest for it.
coming off of I-80 take the hwy 965 north exit, go all the way through north liberty to the last stop light. there is a store called corridoor convenience there. take a right. go until you get to a 4 way stop sign. take a left and stay on that road until you cross the reservoir at mehaffey bridge. then go up the hill, slide to the left a little bit and take the 2nd driveway on the lefthand side. it has a sliding metal gate. there aer brown signs for the raptor center and other park type things. the archery range is down a dip and immediately on your left hand side.