Here are some of my regular routes for gravel (when the trails are too wet).
Two mile route out to the mound from the Rotary Arboretum.
Five miles out 1750 road to 40 highway - very pretty, secluded road.
Ten miles out to Clinton from Martin park.
Big loop of the Scenic River road from Martin park.
Stair Step and Wild Horse road from the KU Field station.