OverviewThis route is simply a variation of the Southwest Chutes. The approach is the same with the variation coming on the actual climb. It is a fairly difficult hike to get there and I would recommend at least a 3 day trip (hike in/summit/hike out) but it could be done in less. I also have to say that the route is a little more difficult to find than some other pages suggest and the terrain is more difficult too. The second two passes would be very difficult to climb with large packs so I would recommend covering them on the summit day.
Getting ThereAs I said before, the approach is the same as the southwest chutes approach. From South Lake take the trail towards Bishop Pass. Follow it for about 6-7 miles, over the pass, and partially down the other side. At one point near the bottom of Dusy Basin you will see a series of long skinny lakes. When you see the lakes, the trail will cut back and head towards the PCT. When that happens, try to find a small trail leading towards the apparent pass (Knapsack pass). The trail will only last for a short time and then you have to begin going cross country for about 1-2 miles. Make your way to the end of the lake (near the bottom of Knapsack pass) and you will find some decent camping spots. Unfortunately, there is little shade, but it makes a decent base camp. Make sure you get a good night of sleep because the next day (if you chose to hike Sill) will be a very tough one.
Route DescriptionFrom the bass of Knapsack work your way up a large rock on the right side that creates a long incline. We found this route to be the best for getting over the pass. Near the top of the incline, work your way to the left a little and follow the valley up to the top. From the top, try to countour around as much as possible towards the Barret lakes. From there follow a ridge that runs towards Potluck pass. The ridge will take you all the way up to the pass and then the tricky part begins.
From the top of the pass you can see into the valley you need to follow to get to the base of Mt. Sill. There is a bit of a trail that countours into the valley, but there are some very difficult sections with quite a bit of exposure. 4 out of our 7 group members turned back at the point because of the danger. Nathaniel continued on the trail and my friend Evan and I turned back a little before we found some natural switchbacks that made a little safer, but longer route. We made our way down a ways before having to climb back up a snow patch and some boulders to reach Nathaniel. From there we made our way North through the valley with one stop for lunch and one to get some water from the snow melt dripping off the valley walls. At the end of the valley there is a steep snow patch that goes up and to the west. During this section ice axes and crampons would have been very helpful, but we have quite a bit of experience getting up steep snow (probably at least 75-80 degree incline) so it wasn't too much of a hastle. At the top, you will reach a large boulder field leading up to Polemonium glacier and you will see what looks like the Summit of Sill to your right (North).
At this point, we countoured around the North end of the valley along a large boulder field. Again, this looked like the base of Sill, but it was difficult to tell. After a short while, we saw what appeared to be the first chute and we decided to try it. We made our way up which was extremely difficult due to elevation and the incline, but ropes were not neccessary at all. Near what we thought was the top, we headed East just a little and came out on a ridge looking into the South Fork of Big Pine creek area. Looking east we could also see the very impressive face of Sill and the Summit which was still a few hundred feet above us and a few hundred yards away. We made our way along the ridge directly to our west, which was very dangerous. It drops about 750 feet straight into the Big Pine side and about 30 feet directly opposite. At one point we were holding the top of the ridge with our hands and walking along a steep slope with a 30 ft. drop. I will post a picture to show this, but it was probably about class 4 considering the danger factor. Once we made it to the other side, we felt grateful to be alive and grateful we didn't have to go down and around the ridge. We continued making our way along the ridge, but down a ways because we had had our fill of danger for the moment. after a few hundred feet of countouring and climbing we had to descend maybe 50 ft to go around a second drop off. At that point we were on the main part of Mt. Sill and we made our way into the first chute which took us near the top. There was one more little dip near the summit, but it can be easily traversed with a little jump down and a relatively technical move around a corner back up the other side. From there it is a straight shot to the top! See the picture I posted if you want to visualize the route we took!
This hike/climb was a pretty difficult day. It ended up being about 9 miles round trip with a large amount of ups and downs as far as elevation. It would be possible to get closer, but as I said before, climbing Knapsack pass with a pack would also be very difficult! The way we climbed it was certainly doable especially for us three young guys. If older members of your group would want to make it, you would need an early start.