Fifteenmile
17.6 miles of challenging singletrack, long climbs and stunning viewpoints. Park at the 15 mile campground. Follow the lower two miles of the Lookout Mountain trail along 8 mile creek. The trail follows the 456 and 457 trails. Be prepared for technical descents and grinding climbs. (more detailed directions to come)
To get there: From Hood River, head 31 miles south on hwy. 35 to forest road 44 on the left. Drive up road 44 5.4 miles to the Bottle Prairie trailhead on the left. (1 hour) Or continue to the right turn for Flag Point, road 4430. Drive 4 miles to the 15 Mile campground and start here. The loop is enjoyable both directions

Rode it Sept 13th, four trees to climb around now. A great 10.2 mile loop from 15 mile campground, or a longer lollipop from bottle prairie.
Rode it from the Bottle Prarie TH, yesterday (Fri, 7/10). Trail is in great shape. One log over the trail, clear otherwise. Still one of the most beautiful and remote trails in HR area. Suggest riding it in a counter-clockwise direction–no pushing required on the climb.
My garmin shows just under 21 miles total, round trip, from Bottle Prarie.
Fifteenmile is open and clear of blowdown.