You can run on the Mopac trail, it is located on 84th street, between O and A. It is limestone with mile markers, and it goes longer than you can. A lot of the time, I will take the Mopac out to a country road and branch off and create my own route.
Or
Try the Murdock Trail, it runs east and west on the North side of town, about half of it is limestone, not as big as Mopac
Or
Just drive out east and get lost on some awesome country roads. Once you get east of 84th street you will start to see some. They are pretty basic, rolling hills and almost always are in country mile blocks. I love the country roads in the fall.