Beginning at Olallie North Trailhead, Olallie Trail #3529 starts a climb up a steep ridge to the north of King Creek. The trail travels through a coniferous rainforest, occasionally breaking out of the forest onto rock outcroppings and madrone groves. The trail travels southeast, climbing the ridge, then winding along the ridge between peaks and mountains before reaching Forest Road 1993 and Pat Saddle Trailhead.
The trail continues south from Pat Saddle Trailhead, immediately entering the Three Sisters Wilderness and following a ridge around to the base of Olallie Mountain. The trail continues downhill past Olallie Mountain along the northeast edge of Olallie Meadow and through Bear Flat. Bearing south, the trail passes the upper reaches of French Pete Creek and wraps up and around to a ridge over the South Fork McKenzie River drainage. The trail then drops steeply down the ridge along a tributary of the South Fork, leveling out before reaching its terminus at South Fork McKenzie Trail #3327 near Olallie South Trailhead.
Trail description from the US Forest Service website.