In Oregon's Mt. Hood National Forest, the summer sun dries out the backcountry ski trails, opening them up for mountain biking along ridges and through old-growth forest with views of 11,000-foot mountains. Take advantage of the skiing infrastructure and overnight in one of the five rustic cabins of the Cascade Hut System. Each 16-by-16 hut (they go for about $100 a night) contains eight beds equipped with sleeping bags, a stove, and a cabinet stocked with pasta, soups, Clif bars, and pancake mix. "You can stay on the trails for days with just your bike," says Kirt Voreis, a Bend, Oregon, resident and former pro racer. There are more than 140 miles of trails, including a tough four-day loop that circles Mt. Hood.

Day 1
Start in the town of Hood River and pedal through the Columbia River Gorge National Scenic Area to the Surveyor's Ridge Trail, a 13-mile stretch of open-air singletrack. Steel yourself for this brutal day – by the end you will have climbed a whopping 6,100 feet. Sleep at the Surveyor's Hut, which, at 4,100 feet, has the best overlook of all the huts.

Day 2
From the Surveyor's Hut, take the flat but twisty and technical Gunsight Ridge Trail along the spine of a ridge, with nothing between you and Mt. Hood except the Douglas fir-filled valley. Stay at the Barlow Hut.

Day 3
This is a day of long climbs and steep downhills. You'll start with a five-mile ride up Barlow Road, part of the historic Oregon Trail, and then bomb down the Pioneer Bridle Trail, with sloped turns and creek crossings, before the big 2,500-foot climb (on paved roads) to Lolo Pass and its hut.

Day 4
It's all downhill back to Hood River on fire roads that look out on Hood River Valley's farmland.