To access from Ketchum, Idaho, drive south on Highway 75 until reaching East Fork Road at a stoplight. To access from Hailey, Idaho, drive north on Highway 75 and turn at East Fork Road as well. Follow this paved road through many different subdivisions until reahing the old mining town of Triumph, which has no services.
Continue past the small town, where the road becomes gravel, and turn left at the first major fork, indicating the trailhead for Hyndman Peak.
Follow this good gravel road to its end. The last mile is a bit bumpy but all cars should be able to make it. Park at the Hyndman Peak Trailhead.
Black Rock Dike Route Overview
The Black Rock Dike Route up Idaho's Old Hyndman Mountain beckons scramblers and peakbaggers from all around. Its notoriety as being a surreal steep scramble up one of Idaho's most ruggest mountains promises not to dissapoint those in search of a true adventure.
An ascent of the route takes full commitment of a day and is not easily reached, and, although rated class III, the route involves some exposure and a very steep section of climbing.
Take Hyndman Creek Trail for three miles as it meanders up the beautiful valley below Cobb Peak. Near the base of Cobb, right before the 7,800' contour line, and at the base of an unnamed stream that flows from Peak 10,292, a faint, unnmarked trail will lead east away from the main trail. This is Big Basin Trail and is easily missed to keep a keen eye.
The Big Basin Trail quickly fords Hyndman Creek, which is difficult most of the year, and heads northeast slowly gaining elevation. About 1.3 miles after the start of Big Basin Trail, or at the 8,600' contour line, leave the trail and head for the bain immediaetly west of Cobb Peak. Navigate yet another crossing of Hyndman Creek and climb through a complicated series of cliff bands to reach an unnamed lake at 9,758'. It is best to remain close to the stream for good footing.
From the lake, continue heading up the valley, and, depending on what time of year it is, this may be a quite marshy area. Climb through another set of cliff bands, (a common characteristic of high Pioneer Mountain Cirques), to reach another unnamed lake at 10,241'. From the lake, climb on increasingly steeper terrain 3/4 of a mile to the saddle between Old Hyndman Peak and Pt. 10,442. A series of towers would make it difficult to save some mileage by heading directly up the southwestern slopes.
From the saddle turn west and begin climbing Old Hyndman's east face, aiming for a small, obvious, dike of black rock that cute the face. Until this point, the route has been mostly boulder hopping, but as it nears the base of the dike, the rock becomes loose.
If not soloing this route, a helmet is invaluable at this point.
Begin climbing the dike, which is only about 1 1/2 to 2 feet across, and almost vertical, by using quite solid handholds. Depending on the time of year or recent traffic through the gully, it may be filled with a bit more loose rock than other times, making it quite diffiult. While the first few yards may be the most difficult technically, the upper portion of the dike may a bit much for those afraid of heights as this section of the climb is very steep and a fall would entail a painful ending. It appears the face just to the north of the dike is easier, however, that is not true. Once at the top of the dike, it is a mere few feet to the summit.
A helmet is a must if there is more than 1 person attempting this route. Those not comfortable with climbing and a bit exposure may find a rope helpful but certainly not a neccesity.
If the Black Rock Dike is snow filled, this becomes an advanced snow climb and should be reserved for experienced mountaineers.