Angel’s Window, an arch formed in the Kaibab Limestone cliffs above Unkar Canyon, developed under a unique set of circumstances; the climate of the Kaibab Plateau is naturally cool and moist providing ample water and freeze-thaw processes necessary for frost action to take advantage of natural weaknesses in the rock, and the rock is well-jointed (from compressional stresses and folding) and well-bedded, both factors allowing water easy access.