skipped over a few posts... but...
i know on blm land in california they have implemented passes and permits. Glamis is a prime example. 100 bucks for a year, 25 bucks for a week. fines for not having one were the same as an annual pass, and on top of that you were required to buy a pass for that time. whether a annual pass, or a week pass.
for washington you could put on the table, for 4wheeldrive use on dnr lands, you must participate in so many hours of working parties at your local dnr orv area, or pay $xx for an annual permit, or $xx for a week pass. similar to national forest lands also. that would help generate money for trail repairs, upgrades, (the unlikely event that we could build a new trail) or any campground needs also. Which would help increase the number of people at the work parties and increase revenue for trail related needs or enforcement of the area. just a thought on the passes idea. i'm never keen on buying passes, but if it's something i love to do, i'll make the time to help the trail system out, over paying anyday.
or you can broaden it by all users, ie the guys parking for dirtbikes and such must have at least a hang tag on the parked vehicle, the dirtbike or atv shouldn't be required to carry one per vehicle. just each street legal vehicle must have one... ie the tow rig for the buggy, or the guy that drove needs to have one in the window. when they buy their permit, they could designate what they do, ie dirtbike, or 4wheel and funds could be appropriated from there to the needs of the parks.
i know it's not a 123 process for implimenting something like this or if it's even possible in washington.
here's some info on their passes for the imperial dunes
http://www.blm.gov/ca/st/en/fo/elcentro/recreation/ohvs/isdra/dunesinfo/permitinfo.html