Lots of incredible trails to choose from in this area--downhill/shuttles; short loops; or all day trips that never cover the same trail twice. Flat Mountain is a round dome, and there is a gravel road that circles it halfway up. Lots of trails above and below this road, and elevation gain ranges from moderate to long and arduous. The trails are maintained by motocross club, and are closed to infernal combustion engines during fire season. You absolutely must have a map and local bike shop advice before venturing here.
How to get there:
From Corvallis, west on Hwy 34 towards Waldport. After turning south on 34 past Philomath, go ~5.5 miles, then left on Bodkin Road (first left after Decker Road--both Decker & Bodkin intersect Hwy 34 from east); go ~.6 miles, and park at Y. If you're on Hwy 34 and you're driving uphill through curves, you've gone too far. Again, you must check with locals for maps and specific trail advice before traveling here.