From State Route 970, turn left from eastbound/right from westbound onto Teanaway Road
Proceed 13.00 miles/21.00 km to the fork at the end of the pavement, just after the 29 Pines Campground;
Take the right fork onto Forest Road 9737 (noted as North Fork Teanaway Road on some maps) and continue 8.00 miles/12.90 km, for a total of 21.00 miles/33.80 km from State Route 970
Turn left onto Forest Road 9737-120 (road name may not be posted), just past Camp Wahoo!
Proceed 0.30 miles/0.50 km to the parking area for the trailhead and De Roux Campground
Views of Mount Stuart and its retinue of rugged peaks are highlights of this challenging hike. Koppen Mountain Trail, Washington.
Spectacular views await the hardy hiker atop Koppen Mountain. However, this arduous hike is not for the faint. The summit is reached by a combination of three trails that increase in intensity as they progress from a gradual rise to a moderate climb and, finally, a pitched ascent in thinning air. From the trailhead, the Boulder De Roux Trail crosses the North Fork Teanaway River and follows its tributary, De Roux Creek, through open woodland. Views begin to open as the De Roux Spur Trail then switchbacks moderately up the saddle between Koppen Mountain and De Roux Peak. From the saddle, the Koppen Mountain Trail pivots steeply upward with nary a switchback, scaling the ridge to the summit at just over 6,000 feet/1,800 meters. A 360-degree panorama encircles the stony pinnacle. The ascent is a bit of a scramble on loose scree, sometimes thinly scattered like marbles over solid stone, and the descent over that same terrain can be treacherous — be sure to equip yourself with traction gear of choice. (Falls would not likely be deadly, as the trail avoids exposure, but could result in injury nevertheless.)
While the magnificent views are Koppen Mountain’s star attraction, other features add seasonal interest along the trails. In spring and early summer, a selection of wildflowers common to both sides of the Cascades populates the trailside from valley to summit. Surprisingly, an assortment of butterflies also ascends the mountainside in search of mates and nectar at the summit. In early summer, large cicadas drone stridently and constantly throughout the wayside. In late summer, abundant blueberries sweeten the woodland understory. At mid elevations near the saddle, outcrops of the greenish stone serpentinite add interest underfoot.
Koppen Mountain’s relative remoteness and challenging pitch offer opportunity to enjoy wilderness solitude away from the crowds that throng even nearby trails. Only the occasional rumble of a vehicle on the forest road far below breaks the quiet thrum of nature pervading this secluded peak.
Throughout their distance, the trails duck in and out of patchy conifer forest, which affords increasing views of the surrounding peaks. Not far from the trailhead, a sturdy bridge carries the Boulder De Roux Trail over the North Fork Teanaway River with a glimpse of Esmeralda Peak’s eastern pinnacles beyond. Boulder De Roux Trail, Washington.At approximately 1.25 miles/2.00 km from the trailhead, watch for the De Roux Spur Trail to branch left from the Boulder De Roux Trail, as indicated by signs posted on separate trees. Take the De Roux Spur Trail to begin climbing the saddle between Koppen Mountain and De Roux Peak. Boulder De Roux Trail — De Roux Spur Trail, Washington.As the trails climb, the massive ridge across the North Fork Teanaway River appears. The ridge and its many apparent summits are unnamed, except for Point 6494, or, Longsway Peak sloping down its northwestern end (here, the leftmost peak on the ridge next to a higher but nameless outcrop) and Teanaway Peak anchoring its eastern end (here, on the right). De Roux Spur Trail, Washington.Rocky outcrops along the trail are composed of serpentinite, a greenish stone distinctively tinted by its mineral content and formation. Because few plants are able to grow on serpentinite, views from these vantages are naturally preserved. De Roux Spur Trail, Washington.Keep an eye out for a variety of unique wildflowers throughout the trails’ wayside woodlands, including, top row, left to right, subalpine fleabanes (Erigeron glacialis), common yarrow (Achillea millefollium), lupines (Lupinus spp.), white rhododendrons, or, Cascade azaleas (Rhododendron albiflorum), and Cascade asters (Eucephalus ledophyllus); center row, left to right, white-coiled louseworts (Pedicularis contorta), Cascade beardtongues (Penstemon serrulatus), mountain, or, magenta paintbrushes (Castilleja miniata) (pink form), thimbleberries (Rubus parviflorus), and liverleaf wintergreens (Pyrola asarifolia); and bottom row, left to right, sharptooth angelicas (Angelica arguta), scarlet paintbrushes (Castilleja miniata) (scarlet form), pyramid spirea (Spiraea x pyramidata), western, or, Sitka columbines (Aquilegia formosa), and wood roses (Rosa gymnocarpa). Boulder De Roux Trail, De Roux Spur Trail, and Koppen Mountain Trail, Washington.At approximately 3.00 miles/4.80 km from the trailhead, the Koppen Mountain Trail departs left from the De Roux Spur Trail at the top of the gravelly saddle between Koppen Mountain and De Roux Peak. Look for stone cairns marking the otherwise easy-to-miss fork, visible here on the left, and a couple of campsites in the forest beyond. The De Roux Spur Trail continues down a stony meadow on the other side of the ridge; if you find yourself going downhill beyond the saddle, it is an indication that you have missed the turn. De Roux Spur Trail — Koppen Mountain Trail, Washington.Near the summit, the Koppen Mountain Trail’s pitch increases dramatically, accentuated all the more by the loose scree and thin air that further slow upward progress. Koppen Mountain Trail, Washington.From its summit, Koppen Mountain’s grand view encompasses a swath of the Wenatchee Mountains that includes, left to right, Hawkins Mountain, Esmeralda Peaks, Fortune Peak, Ingalls Peak, Mount Stuart (center and highest), Sherpa Peak, Argonaut Peak, Dragontail Peak, the Longsway-Teanaway peaks ridge, Iron Peak, and Earl Peak. The summit also surveys the route climbed, down the ridge to the trailhead far away in the cleft between Esmeralda Peaks and Longsway Peak below Mount Stuart. Koppen Mountain Trail, Washington.On a clear day, Mt. Rainier tops the distant horizon in the summit’s southwestern view. Koppen Mountain Trail, Washington.Despite its austere stone, Koppen Mountain’s summit nevertheless hosts an assortment of spring and summer wildflowers, including, top row, left to right, showy Jacob’s-ladder (Polemonium pulcherrimum), alpine buckwheat (Eriogonum pyrolifolium), and broadleaf stonecrop (Sedum spathulifolium); center row, left to right, mountain monardella (Monardella odoratissima), scarlet gilia, or, skyrocket (Ipomopsis aggregata), and Davidson’s beardtongue (Penstemon davidsonii); and bottom row, left to right, sulphur-flower buckwheat (Eriogonum umbellatum), Nuttall’s linanthus (Leptosiphon nuttallii), and arrowleaf balsamroot (Balsamorhiza sagittata). Koppen Mountain Trail, Washington.In summer, butterflies are surprisingly abundant at the summit and other upland clearings, likely the result of “hilltopping,” a courtship behavior in which males fly to high points to demonstrate their vigor to prospective mates. Here, one of several subspecies of Edith’s checkerspots (Euphydryas editha ssp.) savors nectar from the blossoms of an arrowleaf buckwheat (Eriogonum compositum). De Roux Spur Trail, Washington.
