The southwest approach route for the Skamania County Highpoint is a route originating at Stagman Ridge. This route is not the shortest or longest approach, nor is it the easiest or difficult approach... it is somewhere in the middle.
This route offers a good combination of on-trail sections and off-trail sections. If timed right (usually July during most normal years), the off-trail part of the route tends to be a straightforward snow-covered approach rather than the normal loose rock/dirt approach associated with Mount Adams (and Cascade volcanoes, in general). Most of the slopes encountered along the route, until near/at the west ridge of Mount Adams itself, tend to be gentle enough for avalanche conditions to not be a problem if snow is present.
Of course, despite this aspect, it is always recommended to wait until after snow has consolidated and avalanche danger has at least mostly passed.
No glaciers need to be traversed for this approach, and the route's low usage allows for many miles for enjoying the scenery.
FROM TROUT LAKE, WA:
1) From the intersection of ALT-141 and Mount Adams Recreational Highway (i.e. gas station at the intersection), head north along the Mount Adams Recreational Highway.
2) After 1.3 miles, a "Y" intersection is encountered. Veer left onto Forest Service Road #23 (paved).
3) After 7.5 miles along FS-23, turn right onto Forest Service Road #8031 (unpaved).
4) After 0.3 miles, a "Y" intersection is encountered. Veer left to continue along FS-8031.
5) After 3.1 miles further, take a sharp right turn onto Spur Road #120.
6) Follow Spur Road #120 for 0.7 miles, until its end. Stagman Ridge Trail #12 begins at the parking area at the end of the road.
Trailhead For Stagman Ridge Trail #12
1) Follow Stagman Ridge Trail #12 for 4.1 miles until its end, at the intersection with the Pacific Crest Trail (PCT).
Stagman Ridge Trail #12
2) Turn right (east) and follow the PCT for 0.4 miles, until the PCT turns north. However, the "Round The Mountain" Trail #9 continues straight (east).
3) Follow "Round The Mountain" Trail #9 for 0.1 miles further, until at the beginning of the vast Horseshoe Meadows.
4) From Horseshoe Meadows, leave the trail system. Head NNE from the meadows, around the west side of a tiny forested hill located on the north side of the meadows.
Entering Horseshoe Meadows, Ready To Head Off-Trail...
5) Continue hiking in a general northeast pattern towards the west ridge, off-trail for approximately 3.5 miles.
Heading Northeast Towards West Ridge Of Mount Adams...
6) Ascend to the rocky west ridge, and estimated location(s) of the Skamania County Highpoint (8920'-8940' elevation).
Ascending West Ridge Of Mount Adams...
ROUNDTRIP HIKING DISTANCE
: ~16 miles (but exact route chosen and conditions may cause distance to vary)
Here is my own route path during July 2010, as seen using "Google Earth":
Redwic's July 2010 Southwest Approach Route For Skamania CoHP
NOTE: Exact route, coordinates, etc. might change depending upon conditions. Although this route tends to be fairly straightforward, use good judgment when determining proper routes.
Trekking poles, standard hiking gear, 10 Essentials
IF SNOW IS PRESENT:
Ice axe, crampons