Use the Elbow Lake trail to approach. This starts at the end of the East Fork of Mill Creek Road, and follows Sage Creek to a divide, then drops into the Elbow Creek drainage before ascending to the lake. This is an 8-9 mile hike on good, steep trail. From Elbow Lake, ascend to the right of the falls without gaining too much elevation on the slopes to the right. When you reach a small pothole lake with no apparent outlet (this is NOT the lake that forms the falls, but a minor depression just East of it). Snow will often be found on the slopes above this feature. A large chimney-like gully forms the West end of the South face. Start in there. Caution: There is a large 'gash' cutting through the lower cliffs of the South Face. This feature does not reach the upper bench, the chimney that you want to follow starts higher and to the right of the gash. Also, if you take the left side of the pothole lake to approach the gully, use caution if the bank is covered in snow; the far end of the lake does not have much solid ground to cross, so be sure of the snow!
Follow the gully to a notch where it becomes easy to traverse out onto the upper part of the South Face. Cairns will be found marking multiple trails on this section. The route traverses (climber's right) to a shallow gully, then back left, exiting where the West Ridge is met. A short move gets you up and onto a large ledge that overlooks the spectacularly exposed North side of the mountain. This ledge is apparently very dangerous with snow, so be careful in the early season. Move to the far end of the ledge, making a short, exposed 3rd class move. Another 10-15 feet of 4th class gets you on the summit ridge. These moves are not trivial, especially on the descent. Retrace the route to descend. There have been rappel anchors placed on the summit in the past, but they are not often used and should be inspected carefully.
An ice axe and good boots are a must in the early season. If the upper part of the South Face is snow covered, this climb is difficult to follow. The technical sections are not long enough to require a full rope, but some cord may be useful to protect the exposed summit block, especially if there is snow on the ledge. During the winter, Cowan Falls forms an ice climb (WI 4).
This climb has been done round trip from the trailhead in the winter!