To access Columbia peak, follow the Mountain Loop Highway east from Granite Falls to the Barlow Pass parking area (30.5 miles). From here, follow a gated gravel road 4.0 miles to the old mining town of Monte Cristo. A mountain bike is not necessary, but is recommended as a time saver.
On the far right edge of the picture, notice an obvious rock and heather slope which will allow you to bypass the cliff bands on the 6000' high point in the ridge. After climbing this slope, the route will transition to the south side of the ridge. Now you should have a view that looks something like the photo below.
Notice the cliff band that terminates as a rocky buttress in the center of the photo. The climbing route takes you around the left side of this buttress, then up and right to access the gully on Columbia's SW face (above the aforementioned cliff band). Before getting into the gully proper, there will be one short section that could possibly be described as class 4, but the exposure is quite minimal. As you enter the gully, it will be time to strap on your brain buckets (also known as helmets). The climbing here is not difficult (class 3), but it is steep, and any rocks kicked loose by your climbing buddy will reach skull-splitting velocity in short order. The far left side of the gully seems to offer easier climbing, but with more loose rock than the center of the gully - which you choose is really a matter of personal preference. As you near the summit, traverse left and clockwise around the summit block. The very last part of the climb will finish on the north side of the summit (class 2).
On the summit, views will rival those of Kyes, Cadet, and even Sloan.