Oregon
In Oregon, snowmobilers have a pretty sweet thing going if they're looking for a groomed trail system. Oregon's snowy, mountainous regions are well represented by extensive groomed paths that provide access to lots of backcountry riding.
And where there aren't any groomed trails, there's usually a Wilderness area (or two). That's certainly not a knock on snowmobilers in that state. Quite the opposite: it's a compliment that the snowmobile community has been able to protect the riding areas they have, especially along the Cascade Range.
Because the state is so well covered with trail systems, don't think that there aren't any backcountry experiences waiting for you. One that we particularly like is near Klamath Falls and Lake of the Woods off the Cold Springs trail system. There's a trail that leads to the top of Pelican Butte. Some sledders stop there but the more adventurous drop off the edge of Pelican Butte and play in the massive bowl on the northeast side. That is some great hillclimbing.
A couple of other islands of mountains in Oregon where you can sled include near the Pacific Ocean in southwest Oregon at Page Mountain. There aren't any groomed trails here but you can boondock in this area, which is served by the Page Mountain Sno Park on Happy Camp Road. The other small riding area is the Steens Mountains in southeast Oregon. The BLM administers that land and would be the best source of information. Log on to the BLM website (www.blm.gov) and click on Oregon and then head to the Burns District.
Most of the backcountry riding we've done in Oregon was in the eastern part of the state in the Blue Mountains, especially near Sumpter and farther north near Tollgate. There is also great boondocking and backcountry riding in Grant County. It's a little more wide open than in the western part and not as heavily used by other winter recreationists.