Architecture

The Lower and Upper Cliff Dwellings were constructed with unworked local rock and adobe mortar. The Tonto cliff dwellings remain standing 700 years later becuase they are protected by a natural cave and starting in 1933, the National Park Service.

 

Walls were constructed of local rock and clay.

NPS Photo/ C. Sadler

The masonry of the Lower and Upper Cliff Dwelling is of clay and local stone. Adobe was used for both mortar and plaster. The a lot of mortar was applied and the rocks were set in it with no special attempt at fine work. The entire wall was plastered over with a thick layer of mud. All water had to be hauled up the steep incline from the spring. The stone is unshaped quartzite, which occurs conveniently and in great quantity on the talus slope below the cliff dwellings. The adobe is creamy tan in color and full of small stones, which inhibited the making of very smooth plaster. The clay was probably obtained from the talus slope, as there are places where a fair supply of it can be secured with a slight amount of work in removing the larger rocks.

Walls were laid in layers 18 to 24 inches high before plaster was applied. The first layer was rounded at the top so that the next layer would give a better bond. After the first layer was dry the next was laid, and so on. Horizontal lines which denote these units are clearly visible on the walls. These are called cold joints.

No foundations were used; walls rested on either bedrock or loose fill. Because the rock faces are irregular, the walls lack stability, though they could reach considerable height. For example, the tallest wall standing in the Lower Cliff Dwelling is 15 feet 7 inches and rests on loose fill. Walls taper slightly from bottom to top and average 12 inches thick, with plaster averaging 2 inches thick. From the number of hand prints still visible, plastering was done by hand. Interior rooms have their plaster stained from smoke.

In addition, the builders did not bond new walls to the old walls. This is ideal for an archeologist wishing to determine the building sequence but it causes structural weakness. Such weakness would not have affected the dwelling while it was occupied and the ceilings kept in good condition. Once the ceilings were gone the walls were more apt to fall apart.

 

Doors were often built in a rectangular shape with wooden lintels.

NPS Photo/ C. Sadler

Nearly all of the doors were originally built in a rectangular or square shape, and then altered to a half-T, or to a narrower rectangular opening. Door lintels were usually made of sycamore or juniper planks.

Roofs were constructed with one main beam across one center axis of the room. This beam rested in the notched end of a vertical log buried in the floor. The ends of the main beam were buried in the walls or rested against the cave walls with plaster around it. Small poles of sycamore and juniper, at right angles to the main beam, ran the length of the room. In some cases, these poles were only long enough for one end to rest on the main beam and the other in the wall.

On top of the poles, and at right angles to them, was a layer of wooden saguaro ribs. The ribs were then covered with clay. Occasionally, a layer of grass or reeds were laid over the saguaro ribs to help ensure no clay would fall into the room below.

The floors were made of hard-packed adobe clay and flat bedrock to create a smooth surface. Bowl-shaped fire pits were found in most rooms.

 

The Lower Cliff Dwelling contains about 20 rooms and may have supported 40 to 60 people at maximum habitation. The Upper Cliff Dwelling contains about 40 rooms, 32 on the ground level, and about 8 to 10 second story rooms. It was occupied for more than 100 years but by 1425 - 1450, many of the people in the Tonto Basin had moved to other areas.