Reading through the many trip reports for Silliman and talking to people about it, it becomes clear that Silliman is not as easy as one would expect. Although, the statistics of 4,500 ft. and 10 mile round trip imply a relatively easy mountain that could be climbed as a day hike, in winter or early spring things can be quit different. The route is covered with snow that makes progress difficult. Worst, the weather pattern seem to be clear in the morning, but getting cloudy and stormy in the afternoon. Many trips to Silliman end with a statement such as: "We made it about 80% of the way to the summit, but alas we did not beat the clouds closing in on an otherwise perfect weather morning." (Rich Calliger)
Our plan was to make this into a 2-day trip, and attempt the summit early on Sunday before the clouds have a chance to play their dirty trick. We started Saturday morning under bright blue sky on the Twins Lake trail. The trail was free of snow until it bends north at the end of the long assent. From there it was mostly firm snow 2-4 feet deep. The trail was marked by an indentation in the snow, but we managed to loose it at one of the creek crossing. We left the main trail at Silliman Creek and followed the drainage high on the right bank. The use trail was not visible as was the main trail to Twin Lakes, and snowshoes were needed to avoid post holing. We setup camp in a nice flat area on the north side of the creek just after it makes the sharp bend to the east.
The bright blue sky that greeted us when we started the hike quickly turned into a complete overcast. By 10 AM the clouds hovered at around 8,500 ft and would have made summiting impossible. This served as a warning for the following day, the summit day.
We finally got rolling at 6:30 on Sunday. The clouds were already forming on the west. We started climbing the steep slopes of the canyon heading to Silliman Lake, and so were the clouds. It was a race against the clouds, so we allow ourselves only short breaks as we were climbing. After staying on the right, we crossed the creek on broad snow bridges well below the lake and continued on the left were there was an open couloir about 25% which made the climbing reasonable.
Once we reached the top of the couloir we could see the summit and continued on the left side of the bowl towards the tree area, which covers the southwest slopes of Silliman. We reached the summit a little after 9:00. The clouds, having lost the race, were getting closer by the minutes. We can see them as a wall rolling towards us. There was not much time for celebration. We took a few photos, signed the register, and headed down. By 9:45 the clouds reached the summit, and a few minutes later the summit was out of view.
A series of long glissades got us back to camp in about an hour, and we took our time heading out. I got back home by 9:00 PM, not a common thing on PCS trips.