Three Fingered Jack is a great first circumnavigation of a volcano. The run is 22 miles with 3150′ of climbing. The start of the loop is easy to get to as it is located on the PCT at Santiam Pass. It’s also easy to navigate as only three trails are used, the PCT on the west side, Old Summit Trail #4014 on the east side, and just .2 miles of the Minto Pass Trail that connects the trails in the NE section of the loop at Wasco Lake.
It’s best to go clockwise on this loop, as there are no water sources on the PCT and most of the climbing is done early. Take to PCT from the Santiam Pass parking lot and continue climbing on the PCT. It doesn’t take long for views of Mt. Washington and the Three Sisters to come into view from behind. Keep climbing up the west side of Three Fingered Jack to the peak at Porcupine Rock, the highest point of the loop at 6500′. Mt. Jefferson pops out on the other side to the North.
Continue on the PCT where the trail descends on switchbacks. This is the last place for snow to melt, usually by mid-July. Take a peek at the north side of Three Fingered Jack to see where the summit has been exposed by glaciation and multiple reds and browns where the volcano has eroded over thousands of years.
The trail descends even more from the switchbacks to Wasco Lake with Black Butte in the distance. This is where Minto Pass trail connects the PCT to the Old Summit trail and is the first water and the halfway point of the loop. Keep the filter in the pack for a little longer as Canyon Creek is less than a mile away. This water comes fresh from the Canyon Glacier, where the Canyon Glacier trail loops from the Old Summit up the mountain.
The trail continues to the Jack Lake trailhead and Jack Lake, which is fed from the Jack glacier. Proceed to several creeks and a meadow that will be full of wildflowers that bloom through July.
The trail slightly descends through a few miles of huckleberries to Booth Lake and Square Lake. Mt. Washington, the Three Sisters, and the Husband again are seen to the south. At Square Lake is a slight climb and then it descends again to the PCT junction and back to the parking lot.