I have updated the Web page for map of the day hikes in Mt. Rainier NP for the inclusion of one trail which isn't in any popular trail guides but in a less known book, "Mt. Rainier Trails" by Paul Hodge published by Sound and Mountain Publishing, 2006.
The trail is the old West Boundary trail which has two trailheads, one off the Carbon Nature trail just inside the Carbon River entrance in the northwest quadrant of the NP. The trail had been abandoned by the NPS since the trail wanders outside the NP onto USFS lands west of the NP.
The trail returns to the NP on the west side of August Peak at a junction which connects to a short trail which ends at a trailhead on the USFS road to the Mowich Lake entrance. From there the trail goes on the west side Virginia peak, crossing the divide to the east side Martin peak and down to the Mowich Lake road.
The Washington Trails Association and the Mount Rainier National Park Association has spent time rebuilding and improving parts of the trail throughout its length and it's hoped it will be included in trail guides in the future. For now its a little traveled trail, mostly because most of its length goes through the adjacent USFS lands which is cleared timber lands.
That's it for now.