The trailhead is at the west end of the Herman Creek Campground, which is located just east of Cascade Locks off the I-84 frontage road. There is a pit toilet and parking for 8-10 vehicles at the trailhead. This is a popular campground/trailhead and the parking can fill early on summer and holiday weekends. If it does, park along the frontage road and hike on the campground access road up to the trailhead.
From the trailhead, the #406 switchbacks up to and then across a power line access road. In another 0.4 miles, you'll come to a well-signed fork—go left (east) here. The trail soon joins an old dirt road which, after going uphill for 0.6 miles, reaches the Herman Camp primitive campsite (water is not readily available here) and a junction with the Gorton Creek Trail #408
Continue straight on the old road past Herman Camp. At 1.4 miles from the trailhead, the #406 becomes a trail again and you pass a junction with the Nick Eaton Trail #447
. Continue eastward to cross several side creeks, including one with a 100-foot waterfall.
At 3.7 miles from the trailhead, you'll reach a junction with Casey Creek Trail #476
going uphill to the left (east). Continue straight ahead on the #406. At 6.6 miles from the trailhead, you'll reach a junction with the Herman Cutoff Trail #410 and the primitive Cedar Swamp campsite. This is a popular campsite.
Continuing on, you'll cross the East Fork of Herman Creek and reach primitive Noble Camp at 7.3 miles from the trailhead. At 8.4 miles, you'll pass a short spur trail leading to Mud Lake and, at 9.2 miles, a junction with the Anthill Trail #406B, an alternative route to Wahtum Lake. About a mile further on, you'll reach the end of the #406 at its junction with Pacific Crest Trail #2000. Turn left (east) on the Pacific Crest Trail and proceed 1.6 miles to the south shore of Wahtum Lake, where there are several good campsites and water is readily available.