February 15, 2026

Start/End: Marshfield Station

Peaks: Jefferson (5,712')

Elevation Gain: 4,080 ft

RT Mileage: 9.98 mi

Duration: 7 hours, 45 minutes

Snow/Ice Difficulty: Grade I

It was my good fortune that a rare perfect weather day presented itself in the Whites on one of the three days I was home for February break, and I pounced on the opportunity to log a winter ascent of Jefferson, usually considered one of the hardest winter 4,000ers. It would be my first bluebird day hike since Monroe and Washington last March.

Although skies would be clear all day, the forecast was for high winds from the exiting clipper system to persist into mid-morning before rapidly tapering off from there. As such, we figured we'd start a little later than usual, but still early enough to be able to get back down before dark. Leaving home at 6:45 AM, we arrived at the Cog Base Station at 9:10, and started hiking 20 minutes later. There was not a cloud in the sky, but we could see multiple snow plumes above treeline on Clay, Washington, and Monroe, indicating that winds were indeed still elevated.

The Jewell Link is currently closed, so to get to the Jewell Trail from the station we instead followed the Cog for 0.1 miles before ducking under the tracks and taking the Jewell Spur another 0.3 miles and then joining the Jewell Trail from there. After crossing a bridge over Clay Brook, the trail entered the coniferous forest and began steadily ascending the western slopes of Clay at around a 15–20% grade. The trail was a highway despite fresh snow yesterday, and obviously quite a few hikers had ascended ahead of us. The morning sun permeated the forest beautifully.

At 4,300 ft, a sign welcomed us to the alpine zone, although treeline was actually another 300 vertical feet above that. We broke treeline just before 11:30. We felt only a light breeze at treeline, but snow plumes persisted higher up on Clay, and a descending hiker informed us that it was still windy up on the ridge. Besides Clay, we could also see Monroe, Washington, and Jefferson from treeline, and there were no snow plumes coming off any of those, which was interesting. The sky above us, though, was probably the bluest I had ever seen, and it was to remain just as blue through the rest of the day.

The Jewell Trail continued up the western slopes of Clay over a mix of krummholz and snowfields. The wind continued to whip the snow around and had drifted over significant portions of the trail, making it occasionally hard to follow. We fell in a couple of small spruce traps, and snowshoes would probably have been the best traction choice for this section, but we only had spikes and had to manage accordingly. After 0.7 miles, we finally met the Gulfside Trail on the south shoulder of Clay, and the worst trail conditions were behind us.

The Gulfside Trail skirts the western side of the Clay summit cone before descending into Sphinx Col between Clay and Jefferson. I had been contemplating bushwhacking the short distance to the summit of Clay, but it is not a 4,000er and so doing so felt kind of pointless, and so we didn't. Later in the day, though, someone did just that. The Gulfside Trail, being significantly gentler than the Jewell Trail, was easier to follow despite the wind still having drifted over parts of the trail. By the time we got to Sphinx Col, winds had finally died down as forecasted, and we didn't have to worry about trail conditions again.

From Sphinx Col, the Gulfside Trail follows much rockier terrain along the rim of the Great Gulf compared to the krummholz and snowfields we had been accustomed to. Fortunately, the trail was easy enough to follow. At 5,400 ft, on Monticello Lawn, at the base of the Jefferson summit cone, the Gulfside Trail detours off to the right, skirting the Jefferson summit cone just as it skirted the Clay summit cone earlier, as it continues towards Adams. Instead, we followed the bootpack up the Jefferson Loop Trail the remaining 300 vertical feet to the summit.

We were duped by a false summit about two-thirds of the way up the summit cone, but fortunately the true summit was not much further. We summited just before 2:15 PM in essentially no wind and under skies as blue as ever.

It was a busy day on the mountain, and we shared the summit with two other groups. One of the groups had come up from Adams and were aiming to go all the way to Washington before descending to the Cog Base Station (they are visible in the third photo above). Despite the beautiful weather, we were a little behind schedule and didn't linger, instead beginning to make our way back down. The descent of the Jefferson summit cone was smooth sailing, and we were back at Sphinx Col in no time.

Ascending 400 vertical feet back to the south shoulder of Clay from the col, on the other hand, was anything but smooth sailing and was instead expectedly brutal. Descending the Jewell Trail back to treeline from the south shoulder was much easier than we had expected now that snow was no longer drifting and the entire trail was a firm bootpack. Below treeline, the trail was still a highway, and we descended the last 2.4 miles back to the Cog Base Station in under an hour. We were back at our car just after 5:00, and winter 4,000er #16 was in the books. The sun was setting just as we got down, and the day ended with a beautiful view of alpenglow higher up on the mountains from which we had just descended. As I wrote in my journal, it was "a 10/10 ending to a 10/10 day."