ApproachThis route involves only about 1500 feet of gain and 6 miles roundtrip.
From around mile 13 on Lee Canyon Road, look for the turn-off to Macks Canyon on your right (north). There is a sign, but it is not obvious. The turn-off is designated by an obvious dirt pull-out on the side of the road with a dirt road heading northward.
Follow the dirt road about 4 miles to the end. Toward the end, the condition of the road deteriorates, but is still passable to passenger cars. In winter, the dirt road will be snowed in and very likely impassable.
Route DescriptionFrom the end of the road, an obvious route heads west into Macks Canyon. Follow the route about a mile or so into the canyon. From time to time, small side canyons will branch off, but stay in the main canyon.
After a mile or so, the canyon narrows and a dirt trail continues in. Follow the trail as it crosses and re-crosses a small stream. In spring time, the flowers and hummingbirds along the stream make it well worth taking a break now and then and enjoying the views. There are many small seep-springs along the route.
After following the trail along the stream for a half mile or so, both the trail and the stream start to die out and become hard to follow. From that point, continue up the canyon and follow the obvious drainage up steepening scree slopes to an east-west trending ridge above (this is the same west ridge referred to in the Winter Route section).
Once at the crest of the east-west ridge, follow it east as it travels up toward The Sisters, which is obvious at this point.
As you progress up the ridge, the ridge turns into a chute between Middle Sister (on the left) and South Sister (on the right). Travel up into the chute on progressively loosening scree and steepening terrain. Along the route, there are excellent examples of the fabulous Bristlecone Pines that can be seen in the higher elevations throughout much of the Great Basin.
At the top of the chute, you will come to the saddle between Middle and South Sister. From this point, you can make a right turn and quickly scramble up to South Sister.
Middle Sister is gained by heading north from the saddle for a short distance to the base of a class 3 chimney . Travel up the chimney for about 20 feet (little exposure) to a small, narrow and exposed ledge. From this point, it is only about 15 vertical feet to the summit. Once at the ledge, traverse to the right and up along a loose and exposed scree-covered ramp to the summit.
Although most would consider the top of the ramp to be the summit, the actual highpoint is a few inches taller and about 100 feet to the north along the exposed knife-edge summit ridge. The traverse to the actual highpoint is only class 2.
A summit register can be found at the actual highpoint.
On a clear day, the far-reaching views from the summit are incredible.
Here's a route overview photo.