West of Portland and east of Tillamook, the Tillamook State Forest has 200 miles of trails open to ATV riding. The Browns Camp OHV area has more than 100 miles of easy to difficult routes for dirt biking.
Some of the better routes to check out are the Firebreak 5 Trail, The Crushers Loop, University Fire Power, and the Airplane Hill Trail. Make sure to check with the Ranger office prior to riding -- these trails are known to close when wet or durning timber sales.
To reach Browns Camp from Forest Grove, head west on SR6 to milepost 33. Turn south on Beaver Dam Road and follow the signs.
Overall, Browns Camp OHV Area is the 2nd most popular dirt bike trail of all 48 dirt biking rides in Oregon.