Mazamas — For the Love of Mountains
The most commonly misspelled peak in Oregon and one of a handful of alpine rock routes, this is a fairly easy day climb. It may look quite challenging from the start, but the technical climbing is just one pitch of easy 5th class rock at the top. Duct taping your boot tops is recommended for the scree descent. An apres climb swim in Diamond Lake is recommended.
Known as “the Lightning Rod of the Cascades”, the striking summit of Mt. Thielsen is the 7th highest peak in Oregon. The peak was named for a pioneer road builder, Hans Thielsen. It is similar in age and structure to Three Fingered Jack and Mt Washington, where glaciation and other types of erosion have left a relatively solid exposed plug of basaltic andesite. The plug is excellent rock in contrast to the rest of the mountain, which is generally poor. There is a small remnant glacier on Thielsen, and thus summiting this peak qualifies one for Mazamas membership.
The first ascent was done in 1883.
Activity Notes
PEAK and ROUTE DESCRIPTION:
Meet in the Thielsen Trailhead parking area at 8AM Saturday, Sept. 29. Hike up and east 3.5 miles to the Pacific Crest trail. Cross it and hike another mile on an ascending traverse using a well worn climber’s trail (loose rack and scree) up the West Ridge to the base of the summit horn’s east face. From the base of the horn, climb the southeast side on one short pitch of fairly solid class 3-4 rock. I will set up a fixed rope and we will use prussiks to climb up. The descent will be via a rappel. The summit is rather small, so we may have to take turns sitting on it. Elevation Gain, 4100 ft. Distance, 8 miles, round trip. Time, 6-9 hours. Return to cars by 5 PM. Spend the night camping at Diamond Lake, or drive home.. We may eat at the resort (Thielsen Room, good but pricey).
Driving Directions
Leave Friday evening or afternoon. From Portland, take I-5 south about 110 miles to just past Eugene. Take Highway 58 (Signed for Oakridge) east for 114 miles to highway 97. Take highway 97 south 17 miles to highway 138, signed for Crater Lake/Diamond Lake. Turn onto 138 and drive west about 17 miles to the 230 junction. Turn north on 138 for approximately 3 miles to the Mt. Thielsen trailhead (which is signed, and is located on the east side in a large paved parking area). Camp either in the parking lot (or adjacent forest), or at the nearby Diamond Lake campground (where the leader will be). There is no water at the trailhead, so either bring enough water, or drive down to the lake to get it. You can also eat at Diamond Lake resort (a mile north on 138, and a bit expensive, but good). The resort also has a motel with rooms to rent, if you want to stay there. To return to Portland, retrace the route.
Emergengy Info:
Please leave these numbers with someone responsible in town, along with this prospectus information.
If the party is late in returning from the mountain (not back or called in by Sunday noon), concerned friends or relatives should first contact Pam Rigor at 503-292-2940. If there is a problem, we will try to contact her by phone. You can also call the Mazamas at 503-227-2345 (closed on weekends, but can use the Mazamas emergency pager activation: 503-227-2345, ext 3)
We will be traveling in the Umpqua national forests. The phone number is 541-672-6601
| Other Information | |
|---|---|
| Driving Distance from Portland | 250 miles |
| Driving Time from Portland | 5 hours |
| General Route Info | summitpost https://www.summitpost.org/mount-thielsen/150419 mountain forecast https://www.mountain-forecast.com/peaks/Mount-Thielsen/forecasts/2797 |
| Expected Duration | Car to car in one day |
| Relevant Books | Oregon High by Jeff Thomas |
| Relevant Maps | USGS 7 minute series, Mt. Thielsen and Diamond Lake Google map https://goo.gl/maps/xg6vS1k4prQ2 |
| Useful Links | GPS Track GPS Coordinates Map |
