And big. Isaac Canyon runs between the Abraham and Isaac peaks into the Court of the Patriarchs. It is accessed by climbing up the South Fork of Heaps Canyon, which can be reached either by the Gunsight route, or via Phantom Valley. This description is via the Gunsight, and is included as a possible ESCAPE route from Heaps after the Phantom Valley narrows, should escape be advisable.
First known descent: Walt Shipley and John Middendorf, February 1990, descending from the first ascent of Abraham via the Radiator route.
Summer or fall
280 feet (80 m)
Rarely travelled; expect difficult navigation and finding anchors.
Helmets, rappelling gear, webbing and rapid links.
COLD WATER PROTECTION
Wetsuits may be needed in colder weather.
Sparse. Bring Plenty.
FLASH FLOOD RISK
Moderate to high - The collection zone of Gunsight, S Fork Heaps and Isaac Canyon are small, but you do have to cross Heaps itself, which has a large collection zone.
Begins at Grotto Trailhead, ends at Court of the Patriarchs Shuttle Stop.
From the Grotto Trailhead, hike up the West Rim trail to West Rim Spring. Take the "Rim Route" trail west (left) from the spring, and up a steep hill. Soon after passing the head of Behunin Canyon, a ridge leading out toward Castle Dome can be seen. Soon after, the steep drop into the head of Gunsight Canyon is admired. Gunsight is not marked on the map, but is the canyon between Castle Dome and Pt 6910. Backtrack from the viewpoint to the start of the ridge, and bushwhack down to the ridge, then down the side into the head of the canyon. Climb down as far as possible, then rappel off any of several sturdy trees into the canyon. Downclimb and rappel into the slot.
The Gunsight is formed by faulting, and is amazingly straight. The same fault forms the South Fork of Heaps and Isaac Canyon. Descend the Gunsight. Numerous rappels and downclimbs will be required. Anchors will not always be obvious, and might require some skill to get. After a long and impressive V-slot section, a more-normal canyon ramble begins, with nice walking in a lovely canyon interspersed with a few interesting rappels. In dry conditions, getting wet can be avoided, but in normal conditions, deep wades or short swims should be expected. After a couple hours, a huge slab that runs into a vertical wall is encountered, which is almost downclimbable, but easily rappelled from a large pine tree. Soon after, the Gunsight feeds into Heaps Canyon at The Crossroads. The canyon is exceptionally lush here.
To continue the Isaac adventure, head up-canyon about 50 feet to where the South Fork of Heaps comes in. The South Fork can be recognized as a 10-foot wide slot that ends in a 7-foot drop about 30 feet in. An interesting boulder problem can be surmounted by a strenuous mantle, or an assist from your partner.
Up The South Fork of Heaps
Hike up the canyon. A few climbing obstacles up to 4th class are easily overcome. A steep sandpile leads to lush garden of pricker bushes, then a final climb up rocks and logs leads to the pass between Heaps and Isaac.
Since this canyon is seldom visited, you may get the chance to exercise your natural anchor skills and demonstrate judgment. Proceed downcanyon, hiking, downclimbing and rappelling. Rappels up to 200 feet may be required. A few old pins and slings are in place for some of the rappels – evaluate these carefully before use. Better anchors may be easily available.
The end is near when the massive walls of The Sentinel across the Court of the Patriarchs come into sight. Downclimb or rappel to an airy perch, then rappel 280 feet to a lovely spring. (An old climber's rappel station can be seen about half way down this final rappel, so it may be possible to do this route with a 200' rope. The anchors at that station should be checked carefully before being used!)
Follow big boulders in the watercourse down to a cliffband, then follow water pipes and social trails left and down to the floor of The Court. Follow horse trails out to the Court of the Patriarchs shuttle stop.