Skiing the Cascade Volcanoes
        Amar Andalkar's Ski Mountaineering and Climbing Site
Ski Mountaineering Photos & Trip Reports Equipment & Info Cascade Volcanoes Ring of Fire Site Map

Table of Contents | Introduction | Ratings | WebCams | Bibliography | Highest Volcanoes | Snowfall & Snowdepth | Monthly Chart | Conifers | Compare | Distance | Sun Chart
  Lassen Peak
  Mount Shasta
  Medicine Lake Volcano
  Mount McLoughlin
  Pelican Butte
  Crater Lake
  Mount Bailey
  Mount Thielsen
  Diamond Peak
  Newberry Volcano
  Mount Bachelor
  Broken Top
  Three Sisters
  Mount Washington
  Three Fingered Jack
  Mount Jefferson
  Mount Hood
  Mount Saint Helens
  Mount Adams
  Goat Rocks
  Mount Rainier
  Glacier Peak
  Mount Baker
  Mount Garibaldi
  Mount Cayley
  Mount Meager

| Mount Thielsen from the NW across Diamond Lake in June
(photo by Amar Andalkar)   <click to enlarge>

Mount Thielsen
    9182 ft (2799 m) .
Location: Cascade Range, southern Oregon,
70 miles (110 km) NW of Klamath Falls
Lat / Long: 43.2° N, 122.1° W
Volcanic Type: Dissected shield volcano
Volcanic Status: Extinct
First Ascent: E. E. Hayden, 1883
First Ski Descent: Unknown, probably not skiable from summit
Skiable Vertical: up to 3600 ft (1100 m)
Timberline: about 8000 ft (2400 m)
Administration: Umpqua National Forest / Winema National Forest
Protection Status:   Mount Thielsen Wilderness
User Fees: Northwest Forest Pass required for parking
(Sno-Park Permit from November-April)

The soaring spire of Mount Thielsen is the highest of several eroded volcanic remnants which mark the central part of the Cascade Range in Oregon. A few hundred-thousand years ago, Thielsen was a broad shield volcano much like its western neighbor across Diamond Lake, Mount Bailey. Several stages of heavy glaciation have stripped away the outer cone, leaving behind only the hard remnants of solidified magma which mark the inner conduits, with broad talus slopes occupying the gaps between the ridges. The summit spire itself requires one pitch of roped class-5 climbing and is unskiable under any conditions. Thielsen also hosts Oregon's most southerly glacier, the tiny Lathrop Glacier, which is located in a small cirque at 8000 ft (2400 m) beneath the craggy cliffs of the north face. However, the steep talus slopes (especially the Southwest Face) provide excellent ski terrain when snow-covered in winter and spring, although they do not retain snow long into summer. Access is simple from the Mount Thielsen trailhead near the resort area at Diamond Lake.

Route Ratings Starting
Quality Effort Ascent Descent
Ski Mountaineering Routes:   NOTE: All ratings are for ski routes only up to the base of the summit pinnacle.
Southwest Bowl
  (to summit climbing route)

5300 ft
(1600 m)
3700 ft
(1100 m)
10 miles
(16 km)
The standard (and safest) climbing route to the summit of Thielsen follows the Mount Thielsen Trail to its junction with the PCT near tree line and then heads up the open, steepening slopes of the southwest bowl to the base of the summit pinnacle. The bowl provides a variety of skiable lines, in early season starting from just below the summit pinnacle on slopes approaching 40 degrees. Several of the lines pass through couloirs between spectacular lava pinnacles which mark the upper portions of the bowl. The bowl typically remains skiable into late spring, but the uppermost portions lose their snowcover earliest due to the combined effects of wind and sun. An alternate slope accessible from the same approach is the northwest bowl, which is skiable from a saddle near 8500 ft just north of the summit, and due to its NW aspect may sometimes have better snow conditions.
(See my ski trip report from June 1999.)
Northwest Bowl
  (from Thielsen Trailhead)

3200 ft
(1000 m)
10 miles
(16 km)
North Bowl /
  Lathrop Glacier

  (from Howlock Trailhead)

5300 ft
(1600 m)
2900 ft
(900 m)
13 miles
(21 km)
Howlock Mountain is a subsidiary peak which lies about 3 miles north of Mount Thielsen along Sawtooth Ridge. This route initially follows the Howlock Trail, but then turns southeast up the Thielsen Creek drainage to reach the meadows at Thielsen Camp on the PCT, beneath the imposing (in fact slightly overhanging) North Face of the summit pinnacle. A variety of slopes are skiable, including the Lathrop Glacier which reaches 8200 ft in a cirque below the North Face, although the upper portions may have severe rockfall hazard.

Upcoming additions: Topographic map showing ski routes.

| Mount Thielsen from the SW along Highway 230 in June
(photo by Amar Andalkar) <click to enlarge>

Useful Web Links:

Umpqua National Forest: Home Page
Umpqua National Forest: Diamond Lake Trail report
Winema National Forest: Home Page
Winema National Forest: Mount Thielsen Wilderness
National Weather Service Office: Medford, OR
National Weather Service: South Central Oregon Cascades Zone Forecast (alternate link)
The Weather Channel: Crater Lake National Park, OR, Forecast
USGS Cascades Volcano Observatory: Mount Thielsen
Deschutes National Forest: Oregon Volcanoes: Mount Thielsen

List of Guidebooks:  (detailed references on the bibliography page)

Cross Country Ski Routes in Oregon West side access routes (skiing info)
Oregon High All summit routes(detailed climbing info)
Climbing the Cascade Volcanoes Standard summit route(climbing info)

List of Maps:

Map Series Scale Topo? Map Names Year Notes
USGS 7.5-minute 1:24,000 Yes, 40 ft Mount Thielsen
Diamond Lake
First map covers everything needed,
  except trailheads are just off the edge
US Forest Service 1:126,720 No Umpqua National Forest 1995 More current road and trail info than USGS maps

More photos, routes, links, references, etc. coming soon...
Please contact me with any suggestions, additions, or corrections.

Previous Page (Mount Bailey) | Mount Thielsen | Next Page (Diamond Peak)
Table of Contents | Introduction | Ratings | WebCams | Bibliography | Highest Volcanoes | Snowfall & Snowdepth | Monthly Chart | Conifers | Compare | Distance | Sun Chart
Ski Mountaineering Photos & Trip Reports Equipment & Info Cascade Volcanoes Ring of Fire Site Map

Amar Andalkar   Seattle, WA, USA   <About the Author / Contact Me>
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