At the heart of the diminutive Mountain Lakes Wilderness (six miles by six miles square) is a caldera formed by the collapse of a volcano in much the same way as Crater Lake. The Mountain Lakes' caldera, filled with dozens of small lakes, is much older than Crater Lake, and its rim shows the effects of the last Ice Age when five glaciers gouged deep valleys into the region and breached the rim in three places.

At the heart of the diminutive Mountain Lakes Wilderness (six miles by six miles square) is a caldera formed by the collapse of a volcano in much the same way as Crater Lake. The Mountain Lakes' caldera, filled with dozens of small lakes, is much older than Crater Lake, and its rim shows the effects of the last Ice Age when five glaciers gouged deep valleys into the region and breached the rim in three places.

At one time, the Forest Service maintained trailheads into all five valleys. Today, you will find trailheads at the bottom of three glacial valleys. This week's hike begins north of the wilderness at the Varney Creek Trailhead (5,540 feet) and heads south to the northern edge of an 8.2-mile loop trail that links to all three approaches.

To reach the trailhead, take Highway 140 past the 47-mile marker and turn right on Forest Road 3637. In two miles, turn left on FR 3664, which dead ends at the trailhead in two miles.

One of the best ways to tour the Mountain Lakes Loop Trail is to launch a day hike from a base camp on the loop. Good camp choices, which can also be extended day-hike destinations, include Lake Harriette or Eb and Zeb Lakes.

The Varney Creek Trail rises 1,150 feet in 4.2 miles through a glacial valley between Mount Harriman (7,979 feet) and Greylock Mountain (7,740 feet). On its lower reaches near the Varney Creek crossing, a few Engelmann spruce trees join a forest fellowship that includes western white pine, ponderosa pine, lodgepole pine and Shasta red fir.

The route becomes rockier as you climb, but like all maintained trails in this wilderness, the worst rocks have been skirted or removed to the edges of the path. A half-mile before the Mountain Lakes Loop (6,690 feet), a view opens to reveal part of the old caldera rim between Whiteface Peak (7,684 feet) and Greylock.

At the intersection with the loop trail, hikers face a choice of destinations. Eb and Zeb Lakes (6,770 feet) lie .4 miles to the south (right). A couple of small campsites position you squarely between these deep, one-acre lakes. From Eb and Zeb the trail rises an exhilarating 600 feet in one mile through forest and chunky rock to a 7,440-foot pass on Whiteface Peak with views west down the Seldom Creek valley to Lake of the Woods and Mount McLoughlin. This is a logical turning around point for a 12-mile round-trip hike.

To reach 6,726-foot Lake Harriette, hike two miles southeast (left) on the loop trail from the Varney Creek Trail junction. The trail passes Como Lake in .7 miles, a green lake that anglers share with kingfishers and other wildlife. After passing an unnamed lake, the trail climbs to a 6,900-foot saddle above Lake Harriette, then dips .2 miles to the lakeshore. This 70-acre blue lake backs up to a massive slope of white boulders that tumble down from the caldera rim.

Look for Echo Lake to the north and remnants of the old Moss Creek Trail, a steep discontinued approach in a glacial valley between Mount Harriman and Mount Carmine (7,882 feet). Beyond Harriette, the trail climbs 1.5 miles through rocky woods to an intersection with the South Pass Lake Trail, a two-mile dead end that drops 850 feet into a deep forest between Mount Carmine and Aspen Butte and accesses a few lakes along the way.

The loop continues with a stiff .5-mile climb to the caldera rim (7,580 feet). Before reaching the rim, be sure to look back for views of little Mystic Lake and the blasted side of 8,208-foot Aspen Butte. (The section of the loop trail along the rim and a side hike to Aspen Butte are described in the Sept. 11 Hike of the Week.)

The Fremont-Winema National Forest maintains 23 miles of trails in the Mountain Lakes Wilderness. Wilderness permits are not required for camping. The most current map of the wilderness is a 2001 topographical map, available from the Forest Service, 541-883-6714, or online from the National Forest Store or Nature of the Northwest. You can also use two 1998 USGS quads — Aspen Lake and Lake of the Woods South.

Mary Beth Lee is an Ashland writer. Reach her at gentlejourneys@ashlandhome.net.