Elevation: 8,170 ft
This peak is not in the book. Published December 2019
Peak 8170 is arguably one of the toughest mountains in the Arco Hills. It behaves much more like a rugged mountain than a gentle hill. It has numerous rock faces and cliffs on its West and Southwest aspects. The easiest ascent route is via the North Ridge from Wood Canyon Trail. USGS Arco Hills
Southwest Spur/Northwest Ridge, Class 2
Date of Climb: May 29, 2019
At the S end of Arco, ID, along US-20/26, there is a frontage road (Highway Drive) on the E side of the highway. Just N of the Conoco gas station, look for the Lost River Motel on the R/E side of the highway. Find an access road here that goes E to intersect Highway Drive. There is a public park of sorts here with a picnic table. When you reach the “T” junction with [signed] Highway Drive, turn R/S and drive 0.3 miles to a [signed] junction. Go L/E here onto 2450N. This junction is directly E of the Conoco gas station.
Drive 1.0 mile on 2450N to a signed road junction. Go L/N here. This is the start of Arco Pass Road. Set your odometer to 0.0 here. At 3.6 miles, the road turns R/E at a corral. At 4.8 miles, you reach a signed road junction. Go L/N here for Arco Pass. Instead, continue straight/E. At 6.8 miles, the road crosses a cattle guard and bends L/NE. At 7.8 miles, the road turns R/E. At 8.7 miles, you reach a signed road junction. Go straight here for Wood Canyon. At 8.8 miles, the road turns L/N. At 8.9 miles, you reach another road junction. Go straight here for Wood Canyon. At 9.5 miles, there is a grassy campsite on the L side of the road. Park/camp here (6,090 feet).
From the parking/camping pullout at the mouth of Wood Canyon, scramble E through sagebrush up onto the toe of the Southwest Spur of the Northwest Ridge. Follow the R/SE side of the rocky ridge crest on easy, open scrub (which thins out and shortens quickly) to reach Point 6910. Continue grinding your way up the ridge as it curves R/E then R/SE to reach a mix of forest and rocky outcrops at about 7,300 feet.
From here, the terrain is a mix of rocky buttresses/towers/blocks (easy to skirt), short open areas of easy broken scree/scrub/grass, and unpleasant forest (mostly mountain mahogany with some pines mixed in). The West Gully (an easy, grassy gully that narrows high up but gets within about 200 vertical feet of the summit) is on your R/S side as you finish the Northwest Ridge to reach the summit ridge. Scramble S for a short section to reach the ridge crest summit. There is a modest cairn on top. The [lower] false summit is to the SE on a long, narrow ridge.
West Ridge (Descent), Class 3+
Same as for the Southwest Spur/Northwest Ridge Route
From the summit, descend directly W and stay close to the ridge crest. Move L/S to avoid any ridge difficulties. You will soon arrive at a major mess of ridge towers and knife-edged buttresses. Drop off the L/S side of the ridge via ledges on a tower/fin to get to easier terrain below (Class 3+/4). This gets you down to another rocky block, which can be skirted on its L/S side. After passing that block, you soon reach an open scrub/grass hillside on the [now] gentle West Ridge.
Cruise down this section with ease. The ridge wiggles a bit—W then SW then W then S—to reach the valley floor. There are two minor rock humps along this final section. Once on the valley floor, angle L/SE to intercept the 2-track jeep track going up Combe Canyon about ¾ mile up from Wood Canyon Road. This is the terminus of the West Ridge Route. The next leg of this journey is a climb of nearby Peak 7194.