Go here: ...
US Forest Service - Pacific Northwest Region ... order maps for your closest forests, and then go driving. Or go downtown to Powell's or a map store and buy them there.
Seriously, just go up in the National Forests and seek out the secondary, lightly traveled through routes and the dead end "tertiary routes" on Federal land. Normally these routes are the ones that do NOT follow the valley floors. They are often poorly or completely unmaintained, and you will see few vehicles. The NFS maps are truly excellent for exploring, but they do NOT show elevation, so you need either topo maps or something like Google Earth to study so that you can figure out stuff like, "will I encounter snow, and at what elevation?" We had massive snowfalls last winter and some of it remains way up high.....
Here is a great resource for current conditions in the mountains - it is a motorcycle forum but these guys take their big BMW Adventure bikes everywhere, and they are always chatting about routes, closures, and conditions: ...
Pacific Northwet - Where it's green. And wet. - ADVrider
I do NOT recommend any ORV areas - the trail conditions will be way too rough for your car and the parks are full of morons...
You might be interested in the Back Country Discovery Route - some sections of the "roads" may be a little too rugged, but you will see some truly marvelous scenery. Maybe travel with another vehicle like a Wrangler for mutual security: ...
Back Country Maps.
I encourage you to carry a gps, a SPOT with the optional tracking subscription, a minimum of survival gear (enough for an unexpected night in the woods), bear spray or a large caliber firearm, and recovery/ emergency gear for your Outback. Always file a trip plan with a friend or relation. It is really easy to get into serious trouble once you get away from the populated lowlands.
Or you could go to the coast and do some beach driving - there are many miles of sand that are open to the public. Wash your car and chassis completely ASAP after driving on the beaches!!!
Be aware that vast areas of Central and Eastern Oregon are privately owned range land, and with few exceptions the access points are gated and prominently posted. It's _very_ frustrating to be driving through miles of gorgeous scenery with inviting dirt roads branching off right and left, and be locked onto the highway corridor by a constant string of locked gates. You really need to focus on the National Forests for easy access.
You are really close to Primitive Enterprises in Portland (on the west side of the Williamette River), which specializes in Subaru off-pavement stuff like skid plates : ...
http://www.get-primitive.com/ ... Order a set of plates and rally mud flaps, and you can pick them up in person and save the shipping charges.
John Davies
Spokane WA USA