Tucked high into the thick, green forest on the western edge of Oregon’s Cascade Range is a water body so clear, so pristine, it is as though a postcard-perfect tropical lagoon exists in the middle of the mountains.

This out-of-the-way slice of paradise draws paddlers, sailors, swimmers, campers, hikers and mountain bikers every summer and fall to its magnificent, but cold, water and distinct sense of remote solitude.

Just where is Waldo?

Known as one of the purest lakes in the world and one of Oregon’s largest at 10 square miles, Waldo Lake is located north of Willamette Pass off state Highway 58, about a 90-minute drive from Bend. Its clear, indigo water fills a basin scoured centuries ago by glaciers. The lake sits at an elevation of 5,414 feet in the Willamette National Forest, just west of the Pacific Crest Trail.

The 20 miles of singletrack that encircles Waldo offers some of the best mountain biking in Oregon. The technically advanced and aerobically strenuous trail is ideal for intermediate to expert riders seeking an all-day outing that will both challenge and wow them.

Mountain bikers can start at one of three campgrounds on the west shore of Waldo and ride the loop in either direction. I usually prefer to start at Shadow Bay Campground on the southeast shore of the lake and ride the loop clockwise — that way the majority of the difficult climbing is early in the ride on the west shore of the lake, and one can finish the ride with a rather long descent on the east side of the lake.

Earlier this week I stopped at Waldo on my way back to Bend from Eugene and parked near the boat ramp at Shadow Bay. Because Waldo is surrounded by dozens of other smaller lakes, the area is notorious for vicious mosquitoes in late June, July and early August.

Sure enough, as soon as I exited my car, the skeeters attacked. But I applied an ample amount of insect repellent and they relented some. After that, I mostly noticed them only when I stopped to take photos or to eat. The mosquitoes offer a good reason to keep moving on the trail around Waldo.

I pedaled deep into the forest on the south end of the lake and eventually arrived at a spot where I could see South Sister and Middle Sister far in the distance across the lake. Smoke from a small wildfire shrouded the tops of the peaks.

The trail on the west side of the lake is quite difficult to navigate in places, as it is lined with roots and rocks that make for a technical ride. Numerous steep climbs only add to that challenge. I was forced to walk my bike up several stretches along the west side of the loop.

Mountain bikers must be careful not to stray onto hiker-only trails that lead into the Waldo Lake Wilderness — bikes are prohibited in wilderness areas.

As the debate on wilderness access heats up, the Waldo Lake area serves as a shining example of passionate wilderness advocates and equally passionate mountain bikers (often one and the same) finding some common ground.

Waldo Lake is one of those areas that the Sierra Club, the nation’s most powerful environmental organization, seeks to protect, but that mountain bikers still want to access. The Sierra Club and mountain bike groups such as the Central Oregon Trail Alliance (COTA) have a partnership to protect roadless ancient forest areas near Waldo Lake while ensuring continued access for nonmotorized recreation groups to certain trails, including the Waldo loop.

The Oregon Sierra Club’s Keep Waldo Wild campaign would add protection to about 75,000 acres in the Waldo Lake area. But the Sierra Club is mindful of mountain bikers, whose numbers have surged in recent years. The plan would exclude logging and motorized vehicles, but it would not restrict bikes from any additional trails.

“The area is heavily used by the mountain biking communities from Bend, Oakridge, and Eugene,” notes the Oregon Sierra Club’s website. “These user organizations are strong environmentalists and are active stewards of the trails they use. … We consider their support as essential to the political viability of adding permanent legislative protection for this stunning High Cascades area of Oregon.”

This collaboration and cooperation could serve as an example for the two sides, as other areas across the West might become slated for wilderness designation.

As I continued pedaling on my ride last week, I arrived at the north shore of the lake, where the trail runs through an area that was burned in a 1996 forest fire. The charred trees in that section give it a distinct flavor from the rest of the loop, as the trail there is quite a bit dustier and shade is nonexistent. Indeed, it was the hottest part of the ride on a day when temperatures reached the mid-80s at Waldo Lake.

I soon arrived at the North Waldo Campground on the northeast corner of the lake, where numerous campers were enjoying kayaking and swimming. The changing colors of blues and greens at Waldo is due to the changing material of the lake bed, which includes areas of sand, mud and rocks.

Waldo’s water is more pure than laboratory-grade distilled water, according to the Sierra Club. Two-thirds of the lake’s water is direct precipitation, and the rest is from snowmelt and subsurface water flowing from an old-growth hemlock forest.

Turning onto the east side of the loop, mountain bikers should be careful to follow signs to the Waldo Lake Trail and not veer onto the Shore Line Trail, which dead-ends at a remote sandy shore. This happened to me, and I ended up adding about 4 miles to an already long, hard ride.

Eventually I worked my way back to the correct trail, and thankfully most of the east side of the loop was a fast descent back to Shadow Bay.

Back at the boat ramp after 24 miles and nearly five hours in the saddle, I was sweating bullets and ready for a dip into one of the purest lakes in the world. The water was nearly as cold as it was clear, but not intolerable. And plunging in was the perfect way to refresh after a hot yet fun day on my bike.

— Reporter: 541-383-0318,

mmorical@bendbulletin.com

Waldo Lake Loop

Directions: From Bend, drive south on U.S. Highway 97 about 45 miles to the Crescent Cutoff, on the right in the town of Crescent. Follow the cutoff road for 12 miles, then go west on state Highway 58 over Willamette Pass to the Waldo Lake access road on the right. Follow signs to Shadow Bay Campground and park near the boat ramp. (About 85 miles and 1.5 hours from Bend.)

Features: Singletrack trail around one of the world’s purest, clearest lakes. The trail is mostly solid and smooth, with several technical sections of rocks and boulders on the lake’s west side.

Distance: Entire loop around the lake is about 20 miles; four to six hours.

Elevation gain: About 500 feet.

Rating: Aerobically strenuous and technically intermediate to advanced.

Season: Summer and early fall.

Editor’s note: Mountain Bike Trail Guide, by Bulletin outdoors writer Mark Morical, features different trails in Central Oregon and beyond. The trail guide appears in Sports on alternating Thursdays through the riding season.