Rarely travelled. 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.