The route mapped here approaches via the Pole Creek Trail and Camp Lake Trail. The same approach can be used for North Sister, so some climbers will turn this into a multi-day expedition and climb both peaks from a basecamp in the middle.

The ascent to Middle Sister follows the climber trail up the valley between Middle Sister and North Sister. The route mapped here ascends the moderate valley all the way to the saddle between the two peaks. The peak is accessed "via Hayden Glacier on the east side,” according to Keema on SummitPost.org. The climb up the valley is an "easy glacier slog to a saddle between North and Middle Sister,” according to Keema. The route then turns left to make the main push for the summit of Middle Sister.

The steep ascent up Middle Sister is fairly straightforward, following the ridge from the saddle almost directly for the summit. That said, the snow and glacier travel continues, with rocks and boulders mixed in.

After you’ve enjoyed the stunning views from the summit, retrace your steps back to the car or your basecamp for the night.

Sources: PeakBagger.com SummitPost.org