Basin Mountain 13,181′, Basin Mountain Southwest 13,240′, Four Gables South 12,801′ and Four Gables 12,720′
Sierra Nevada
Total Time: 13:05
Distance: 17.9 miles
Elevation Gain: 7300′
Crux: Class 4
Trailhead: Horton Lakes TH- no services
Basin Mountain is a striking summit on the Bishop skyline. Flanked by the taller summits of Mount Humphreys and Mount Tom, it is named for a deep, almost caldera looking basin on the east face. While this make for an excellent snow climb and ski descent, I was interested in doing it in dry conditions in order to traverse and link up with Four Gables, netting two SPS peaks in a single outing. Although the final 200′ of the East Face of Basin Mountain is rated fourth class, I was encouraged by Peter Croft to give it a go, as there are multiple class 3 variations to avoid anything too difficult. After all, he had done the climb with his dog, so how hard could the scrambling be? Leaving Mammoth, I drove through the Buttermilks towards the Horton Lakes trailhead, the road in significantly worse condition than on my previous visit climbing Mount Tom after the historic winter storms of 2022-2023. I painfully made it to the turn off for Horton Lakes but quickly abandoned hope of getting much further, not wanting to push it in Holly’s car. There was a large pull off in the road a tenth of a mile back down the road from the junction, and I parked the car and started off on foot up the road towards the trailhead. I cut off cross country before reaching the trailhead proper, climbing steeply uphill through sagebrush and scattered boulders, aiming directly for the namesake basin in darkness. About 2 miles in, I intersected an old overgrown mining road, with a series of switchbacks leading into the basin itself. Bypassing the mine, I continued upwards, utilizing ribs of large rocks and boulders that I hoped would prove to be more stable than the sand and scree that filled most of the basin. This initially worked well, until I reached a large permanent snowfield at 11,500′. I had no traction with me and the lingering snow was bullet hard ice this late into fall. I skirted the snowfield on the right and found extremely loose rock and sand.
This unpleasantness continued even above the snowfield, with no really pockets of solid rock remaining until I was nearly at the notch immediately southeast of the summit. I was starting to feel sandbagged by Peter Croft, and wished that I had climbed the route in snowy conditions. The sun was now illuminating the granite summit rocks above, and I traversed from the notch around to the south, looking for class 3 alternatives.
There were several ramps that seemed like they would go at 3rd class, and I started up a series of ramp systems, aiming for the summit blocks. There were plenty of options, and in general would take whatever crack, gully or ramp had the least exposure. I topped out shortly before 8 AM, not in a record breaking time but also under less favorable sandy conditions. It was too windy and cold for much of a break, so after taking summit photos and wolfing down a few calories, I dropped off the ridgeline to the west.
There was reportedly good scrambling on the ridgeline leading to Basin Mountain Southwest, which was actually higher than the named summit, although hidden from view down in Bishop. The connecting ridgeline started off easy enough, mostly class 2, with the occasional gendarme and spire easily bypassed to the north on talus and scree with small patches of snow lingering from an early season storm. As I grew closer to the summit, the ridgeline narrowed and I scrambled up to a major false summit about a quarter mile from the high point. I was surprised to find no easy way to continue, and tried a series of ramps and gullies that each wound up cliffing out before I could reach the notch below. I wasted about 30 minutes trying to find away off, ultimately backtracking down the ridge and traversing it (easily) on the north side.
The final stretch to the summit had some of the best climbing of the day, with a slabby fin of rock with a series of featured parallel cracks leading all the way to the summit. Although a bit warmer, both the climb of Basin Mountain and the subsequent traverse had taken me a bit longer than expected, and I was probably only 1/3rd of the way through my day if I wanted to tag Four Gables.
Thankfully, the terrain became much easier on descent, the ridgeline quickly becoming class 2 followed by a sandy boot ski descend to a broad connecting plateau south of Four Gables. Similar to Basin Mountain, the named summit of Four Gables was not the true highpoint, which was just a quarter mile to the immediate south. Despite being behind schedule, it was easy enough to tag both the named summit and true highpoint, and I made good time hiking across the barren landscape, aiming for Four Gables South. While the traverse from Basin Mountain to Basin Mountain Southwest had taken about two hours, it took me less than 1.5 hours to cover the distance to summit #3.
I paused briefly for a few photos before continuing north, taking about 20 minutes to reach Four Gables and final summit of the traverse. Although this was my shortest summit of the day, the views were still quite good, with Basin Mountain and Mount Humphreys to the south, Merriam and Royce to the west, Bear Creek Spire and the surrounding peaks to the northwest and Mount Tom to the northeast.
I took a short break before starting my descent, utilizing a class 2-3 gully that began just a few feet south of the summit proper. This descent started off easy enough, but cliffed out about halfway down, forcing me to traverse south down a tricky slab gully to easier terrain below.
Looking at my GPS track later, I had probably missed an easier ramp system that others had used. Oh well. Beneath the gully, the terrain was just loose enough to be tedious but not loose enough to boot ski down, and it was slow going across talus to Horton Lakes.
I dropped a little too low towards Upper Horton Lake, and needed to climb back up and around a collection of slabs and granite cliffs on the north side before picking up a use trail, bringing me all the way back to lower Horton Lake and the main Horton Lakes trail.
I passed a handful of backpackers on the hike out, enjoying the pockets of aspen along Horton Creek turning golden for fall. As the trail rounded the northeast slopes of Basin Mountain, I cut steeply cross country directly for my car, the white dot slowly growing closer in the sage brush below. I reached the car about 13 hours from starting out, a touch longer than I had hoped but with some time wasted on the ridgeline to Basin Mountain Southwest. I hopped in the car and headed back to Mammoth, getting back just in time to have dinner with the family.