I've posted a link to the park before. If you go back a couple of pages, you should be able to find it. Just click on "Map" on that site. The parking lot for the park is really easy to find. From US54, take the Maize Road exit and head south. When you get to Pawnee, turn left (east). The parking lot is on your left before you get to the end of Pawnee.
My brother sent this link to the house which is right next door to the parking lot:
https://maps.google.com/maps?q=10010...ed=0CAYQ_AUoAQ