Just a thought, not sure how it is in Oregon. Have you checked into zoning issues/permits, anything the city/town may want to shut you down for?
We have a place local for us that the farmer "donated" his property (actually his boys run the property). They hold some PNW races, mud bogs and even made a MX track. They have had a few events and now the neighbors and "town" want to shut them down. Too much traffic, noise, mud, etc...... They are getting them with zoning issues and traffic use issues.
Not wanting to be a stick in the mud, and I am all for more areas to play. Just hate to see you go through all the trouble of getting something put together with a lot of time and effort to have it shut down with a piece of paper from your neighbors or such.
If you can get it put together I would go for trails and an area to put together a cross country type track
