Destruction by the Elements
The constant beating of rain and snow, often accompanied in winter by freezing of water in the crevices of the masonry, has sadly dilapidated a large part of the front walls of Cliff Palace, especially those at the northern and southern ends ([pl. 3]) where they do not have the protection of the overhanging roof of the cave.
While the sections known as the old quarter, the plaza quarter, and much of the tower quarter are protected by the roof of the cave, even here there has been exposure and destruction from the same cause. Torrential rains on the mesa in the late summer form streams of water which, following depressions,[18] flow over the rim of the cave roof and are precipitated into the trees beyond the lowest terrace of the ruin. The destruction of walls from these flows is much less than that from smaller streams which, following the edge of the cave roof, run under the roof and drip on the walls, washing the mortar from between the component stones, and eventually undermining their foundation and leading to their fall. The former presence of these streams is indicated by the black discoloration of the cave roof shown in photographs.
A visitor to Cliff Palace in the dry season can hardly imagine the amount of rain that occasionally falls during the summer months, and it is difficult for him to appreciate the destructive force it exerts when precipitated over the cliff. When Cliff Palace was occupied, damage to walls could be immediately repaired by the inhabitants after every torrent, but as the ruin remained for centuries uninhabited and without repair, the extent of the destruction was great. The torrents falling over the ruin not only gain force from the distance of the fall, but sweep everything before them, bringing down earth, stones, small trees, and bushes. At such a time the bottom of the canyon is filled with a roaring torrent fed by waterfalls that can be seen at intervals far down the gorge. The observer standing in Cliff Palace during such a downpour can behold a sheet of water falling over the projecting cliff in front of him. These cataracts fortunately are never of long duration, but while they last their power is irresistible.[19]