In May 1948, a diver went down into the Well to determine its depth and explore the bottom. After coming up from the first dive, he said the water was so warm that he had to remove all clothing except for his swimming trunks. The temperatures at the bottom and on the surface differ by some 4° to 7° in summer. On surfacing from another dive, he remarked that the black muddy bottom was broken by two white mounds of sandy material near the west shore, and that the water in this region was cool. Continued search in this spot did not reveal an actual inlet to explain the cool water or the presence of the limestone mounds, which may have been inlets at one time. Several descents revealed the saucer shape of the Well and a maximum depth of 55 feet near the center. [Illustration: MONTEZUMA WELL AREA APRIL 1958] [Illustration: _Diagram of undercut grave at Montezuma Well._] The Well has a constant flow at the outlet spring of 1½ million gallons of water every day. A person viewing this cup-shaped depression, half filled with water, could easily doubt this statement of flow, for the surface presents a placid and serene appearance. The water, acting like a giant mirror, reflects the blue Arizona sky, and stimulates visiting photographers to take many pictures. On the rim, and in the ledges and caves below, are remnants of former Indian homes—reminders that in the past this body of water stood for more than natural beauty. Its presence made possible a thriving farming community of about 150 to 200 Indians between 1125 and 1400. Archeological features include the remains of two pueblos on the rim of the Well. The larger contained about 24 ground-floor rooms, and the other 15. Three small cliff dwellings are located in the western ledges and several rooms are hidden in a large cave near the place where the Well water goes underground before emerging at the outlet spring. Two burial grounds have been discovered, one on the flat below the Well, and the other near the small pueblo. As mentioned in a previous section, the method in which the Indians at Montezuma Well buried adults was rather unusual. They excavated a rectangular pit in the ground, roughly 3 by 6 feet. About 3 feet below the surface, they broke through a fairly hard 8- to 10-inch limestone layer commonly found underground in this area. After digging about 2 feet below this layer, they dug to one side, underneath the limestone, forming an undercut grave. This was made large enough for the body to lay at full length inside, and to accommodate funeral offerings, usually including pottery vessels. The undercut portion was closed with 3 or 4 large slabs of limestone, which were sealed with mud to prevent any dirt from entering. Then the pit was filled with dirt to complete the burial. Nowhere else in the Southwest are undercut graves quite like these found. [Illustration: _Modern irrigation ditch flows beside lime-coated bank of ancient irrigation ditch._]