Alpine Scramble - Foss Peak/Unicorn Creek

Trip Report

This was my first official trip as a new Tacoma Scramble Leader. I wanted to get a peak I hadn't tagged on the Rainier 100 list, but moderate enough to not stress me out. At first, I only planned on summiting Foss Peak. But after talking to Chris Pribbernow, I was convinced that it might be perfect timing to also summit nearby Boundary Peak. I rappelled off Unicorn Peak on a Basic Climbing trip the week before, so I was very familiar with the approach conditions from Bench and Snow Lakes, plus the scramble up the notch to the base of Unicorn. I could see the ridge from the snow gully to Foss Peak and knew it would be fairly straightforward.

The only question was the condition of the ridge between Unicorn and Boundary. The week prior had low visibility, so I couldn't see the route. Weeks earlier, another group had to turn around due to moats and deteriorating weather. With the rapid snow melt and sunny forecast, I figured my timing was just about right. I reached out to other leaders for more beta, and was greatly assisted by Dennis Kiilerich, David Judish, Jacob Lopilato and Mary Lou Biggs. So the plan was set in motion to scramble Foss Peak, and then decide on Boundary based on group strength and conditions. I was ably assisted by my long-time scrambling buddy Adam Dodge. I made sure participants were comfortable with steep snow travel using crampons and ice axe. I ended up with a small group, but a strong one. Dennis Kiilerich happened to be leading a climb of Unicorn Peak the same day, and we worked together, watching out for each other's teams.

We parked at the Snow Lake TH on Thursday at 7:30 a.m. with plenty of space available. The easy trail to Snow Lake crosses a beautiful meadow with nice view of Unicorn Peak:

There was very little snow on this section. Once past Snow Lake, we had to cross a long boulder and talus field:

We began the steep ascent of the snow gully:

As we ascended higher, we could start to see the summit of Foss Peak:

You can also see why Unicorn gets its name:

We aimed for the saddle between West Unicorn and Foss Peak, then began scrambling the ridge which was mostly snow free, looking back at West Unicorn:

We continued working our way up the ridge until reaching the summit:

The summit has a commanding view of Mount Rainier:

We returned to the snow gully basin, then scrambled up the notch to the base of Unicorn Peak. This is where we met Dennis Kiilerich's team:

Once we viewed the ridge between Unicorn and Boundary, we knew our timing was perfect:

We followed the ridge, avoiding cornices and maneuvering on both sides as needed. There were only a couple of places where we needed to drop slightly on the southern side through trees. As we got closer, we could see the summit block:

Dennis Kiilerich advised us to wrap around the southern side until reaching the southeast ridge. This turned out to be excellent advice, as it was a Class 3 scramble to the summit:

There is a nice view of nearby Stevens Peak:

On our return, we could see how our timing on the ridge was perfect:

We descended the notch just as it started to rain. We were able to get to the parking lot before the worst of the pouring rain:

It turned out to be a special day, with a great group of Mounties enjoying great views. Thank you to Adam and Jo for making my first trip so memorable.

6.9 miles, 3197' ascent, 9:13 total time

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