here's a link to the Tillamook state forest OHV
www.oregonbushhackers.org/maps/tsfmapa.htmlyou can get a map from the state forestry dept. on east 3rd st. in tillamook, and it's waterproof, so you won't spill your
on it! They have gone to great length to produce a high quality map. Very detailed. It has the trails listed for difficulty, all trails are one way travel, and some are for motorcycles, quads, trucks, horses or all of them! The state takes time to maintain them, the maps and trails!! The map is very cool to have. My wifes cousin works for Marlin and he was very impressed on the detail they had in the map! We didn't have a running 4x4 when he was up last time or I would have taken him there!
If you ever get to Bend, they have a couple areas just southeast that has some areas dedicated to offroading, not very big but kinda cool for just messing around, if ya ever over there and have an hour or so to kill! Hope this helps out!
