From the NPS regarding the Pinnacle Peak Trail:
Pinnacle Peak is situated in the middle of the Tatoosh Range at an elevation of 6562 feet, the second highest peak in the range.
Drive east either from Longmire or Paradise on the Stevens Canyon Road to the parking area at Reflection Lakes. The trailhead is on the south side of the road.
The trail begins with a gradual ascent but soon becomes, and remains, a steep climb to the 5920 foot saddle where the trail ends. Hiking boots are recommended since this trail has either a snow or loose rock surface all summer. From the saddle to the top of Pinnacle Peak is a precipitous scramble on loose, unstable rock. Hikers wishing to get to the top should use extreme caution and have proper equipment.