This one starts on a well graded trail that leads up to a beautiful and very popular area of lakes and parkland then switches gears halfway through and you then find your own way up the mountain to the north ridge. From the forest that encloses you totally at the beginning to the total free and alpine environment of an area of snow and rock. All of it can be savored and enjoyed in one long day or in more bite size pieces of backpacking in and camping in a beautiful area and taking another day to do the climb. This may be a county highpoint that is kind of strange as a liner but the nearness of the Jefferson Park and Whitewater glaciers plus many permanent snowfields will leave you amazed by the beauty of the lunar like landscape of this cascade volcano. Fortunately the surveyors line crosses at the 9000 foot mark as a few hundred feet higher on the north ridge would make this an extremely dangerous undertaking for getting the highpoint and even at the 9000 foot mark, don't underestimate the terrain you'll be on.
From Portland, head down I-5 to Salem and take the exit (exit 253) for Detroit, highway 22. Detroit is a place where you can find some groceries and gas and some cafes. From Detroit head east on SR 22 for 10 miles. Between mileposts 60 and 61, turn left on Whitewater Road 2243. This is a well graded road and except for some potholes you'll need to dodge on occasion, follow the road to its end about 7 miles later to the trailhead. A forest service pass is required to park there. NWForest pass are 30 bucks and are good for a year. Cars without them will be ticketed as rangers make frequent visits to the TH. Leave no valuables in your vehicles for the usual reason.
Take the trail to a junction on the ridge (1.5 miles) and turn right (toward Jefferson Park). Follow the trail along the south face of the Sentinel Hills; just after crossing Whitewater Creek find the junction with the Pacific Crest Trail. Turn left here, and continue another 1/2 mile to the outskirts of Jefferson Park. Distance involved to get to Jefferson Park? About 5 should be close to where you will need to leave the main trail and strike out on a use trail towards the mountain itself
Ahead is the area
Head almost due south,crossing a small stream, and aim toward the western of the two ridges which join at about 7400' just NE of the toe of the Jefferson Park Glacier. From here proceed up about 400', cut left across a shallow gully, and pick up the main north ridge of Mount Jefferson (here beginning to trend NW). Follow the ridge through some class 2 bits (drop left around some minor gendarmes)or step onto snow to bypass the gendarmes to a minor saddle at just under 8800'. From here, head south up the ridge stepping on all the highest rocks until you're sure you're above 9000'. Our GPS units were helpful along with a map and compass. One of those rocks was the highest in Marion County. Voila, count it and get the heck outta Dodge.
Getting ready to go down
Overall distance: Roundtrip 15 miles
Elevation gain: 5500+ feet.
Some will be able to dayhike this where some will need to take two days to accomplish gaining the county highpoint. Your call. Actually two days would be a more sensible way to do this one and it'd be much more enjoyable and a chance to savor this portion of Oregon, one of the true beauty spots.
An ice axe is a good idea if you use the snow to bypass the gendarmes or if you come early in the season. Early in the season might also call for crampons. I'd even recommend taking a helmet for a few areas and while helmets might be a bit more than is necessary, it is best to err on the side of caution. Watch your footing at all times if you aren't used to dealing with talus or scree and many rocks that you might trust to put your weight on will move when you least expect it.
Early in the season. Mosquito repellent and possibly even head nets. Water filters for your drinking water is highly recommended. Pre set coordinates
if you use a GPS and good map and compass skills in case of bad weather.
Taken from a trip report posted at cohp.org
After we left the Jefferson Park area, we started looking for a reasonable
way up to the the 7400 foot mark as mentioned by Ken Jones in his trip report. Here's what Bob had to say:
"There were many use trails all over the scree/talus slopes, all of which converged on the north/south lateral moraine leading to the toe of the Jefferson Park Glacier. The scree is loose, but the footing was adequate, making the ascent not too difficult. Where the two ridges converge near the glacier, we turned southeast toward the north ridge of Jefferson. We reached that ridge just north of a hump which was directly above our approach ridge. As the boulders on the north ridge got bigger, we moved around to the east side and ascended the much easier snow to the saddle about 0.1 mile north of the HP. As we approached the county line we touched everything in sight until we were sure we had climbed well into Linn County."
"On the descent we dropped from the saddle down the west side of the north ridge on wonderful scree, then connected to our ascent route by descending a snow arm of the Jefferson Park Glacier. Farther below we tried a different use trail than the one we had ascended, and when it petered out in a draw filled with close growing young conifers, we moved to an adjacent wooded ridge where we found our way down to the meadows near Whitewater Creek, then on to the trail, returning to the cars just before needing our headlamps."