THUNDER MOUNTAIN (9,408' and 9,410') CLASS 1-2
Location: 2.5 miles SSW of Kirkwood, CA
Drive: Take Highway 88 to the signed "Thunder Mountain Trailhead" 0.3 miles west of the local summit marked "Carson Spur Elev 7990 ft," which is 1.8 miles west from the Kirkwood Road junction, or 10.4 miles east from the Mormon-Emigrant Trail junction. A very short section of paved road is apparent on the south side of the highway. A signboard reads, "Thunder Mountain Trail." Here is a big, dirt, primitive parking area for up to 20 cars. A map on the signboard here shows the route and local trail system. There are no facilities (July, 2012). An outhouse is available a couple miles west on the highway at the Silver Lake campground.
Climb: Follow the signed trail southeast. Formerly, a sign warned of unexploded ordinance from avalanche control. Ascend on the main trail through a large red fir forest. The trail climbs and passes to the right of the snow deflecting structures. These are visible from the highway while driving up from the east. The trail switchbacks up along the main northnorthwest ridge, and passes to the right (west) of the higher of the "Two Sentinels," which appears to be a class 5 climb. A signed trail marked by a post indicates the Sentinel Trail going left. Go straight. The trail climbs along the ridgetop, and then passes to the left (east) of "Martin Point (9,250')," and continues along the ridge. Warning signs mark the ski area boundary. The trail switchbacks up through scenic, volcanic mud flow outcrops, and then swings right (southwest) to follow the broad northeast ridge near the summit area. A trail junction marked by a post indicates going straight, or right, to "Thunder Mtn Loop." The lower left fork heads for "Horse Canyon." This junction is some "3" miles from the "Hwy 88" trailhead. Follow the good trail, with a few, very small, short outcrops to pass over or around, to the 9,408' summit which requires a short bit of scrambling. This point overlooks the west side of the mountain, which is quite precipitous.
Back at a major notch, a bit less than 3 miles from the CA 88 start, a hundred foot high crag rises to the main trail's left (east). Proceed on the main trail some 100 yards southward to an unsigned use trail headed right (northwest). This climbs up to the Amador County Highpoint (9,410') shortly, with perhaps some easy rock scrambling. The distances here are in about a hundred yards horizontal, and about 150 feet of vertical elevation gain.
WINTER SKI ASCENT: The large bowl to the north and northwest of the summit mass slopes gently up to the northeast ridge of this mountain, and may make a good, relatively gentle downhill run through the trees in its lower half. This drainage intersects Highway 88 at about Martin Meadow, which is a flatish area along the highway with many aspen groves. Parking here may be a problem during periods of heavy snow.
TRIP STATS: Route A, 1,600 feet gain with an additional 100 feet gain on the return, 3.6 miles one way.
Notes: This trail, Route A, was built recently, and offers an easier, scenic hike for persons less enamoured of cross-country travel. It is a bit dusty at its lower end. The view of Silver Lake to the west is very good from the top. A substantial drop must be made in any traverse over to Thimble Peak to the south, with generally easy cross-country travel, or now perhaps a marked trail, along the open, high, ridge.
From what I might gather (2001), one can ride a lift from Kirkwood Ski Area to the ridge to the east of the summit, for a $10 (?) fee. This trail route leads northwestward to intersect the Route A summit trail, 0.5 mile, below and east, from the point 9,408'. The one way stats seem to be about one mile with a few hundred feet gain. From the post indicating "Thunder Mtn Loop" and "Hwy 88 3," head left (west) to go to the 9,408' point, and right (east) to go to the 9,410' point.
The southwestern summit (9,408'), where Route A culminates, does appear to be slightly higher than the northeastern summit (9,410'), but I have now checked with a water level, and the point 9,410' is higher. The 9,410' summit, for those with CA County HP aspirations, again, is easily reached by ascending some 200' cross-country, up a short, class 1-2 slope, northwest from the Route A trail, about where it connects with the main northeast ridge. A slight use trail, starts after 100 yards, or so, southwest along the main trail from a slight saddle, or deep notch. This use trail is found by a nearby, orange, resort boundary, warning sign.