Sonyok Mountain is on Tribal Indian land and a use permit is needed to go there. I bought mine at the Mangy Moose in Plains but they are available in most sporting goods outlets. The summit has a working lookout but had not been opened for the season when I was there.
I had mapped out three different routes to the summit “trailhead” and opted to drive up from the south off Nestucca River Road. Turn north at an unmarked road/intersection .7 miles west of the NW Boundary Road/Nestucca River Road intersection. Most roads in this area are unsigned. It is highly recommended to take a map and GPS for directional references. Drive for approximately 15 miles on well graded roads through typical forested areas, old clear-cuts and new logging operations. Once onto Toll Road heading east, turn right at an intersection near a map marker labeled BM 2776.