Width of cave at mouthfeet64
Least width of cave, 24 feet from mouthdo45
Greatest width of cave, from doorway to branch in cave in eastern wallfeet74
Shortest distance from line of least width to line of greatest width, as given abovefeet18
From mouth of cave to doorwaydo51
Height of doorwayinches42
Width of doorwaydo33
Length of floor of doorwaydo56§
From mouth of cave to top of slope of ashes at rearfeet84
From top to bottom of slope of ashes at reardo16
From foot of ash slope to rear walldo27
Extent of ashes in turn of cave along foot of wall beyond corner of west wallfeet22
Width of these ashes, from foot of wall to the pool of waterdo22
Width of cave from corner of west wall to east walldo56
From corner of west wall to rear of cavedo47
Height of extreme front from floor at edge of bluff to most projecting ledge abovefeet35
Height from shelf or ledge near front of east wall to general level of rooffeet14
Height from ashes to roof at middle of cavedo10
§ This measure also represents the thinnest portion of the wall separating the main cave from the outer cave.

The walls were, as is usual in caverns, somewhat irregular, there being a narrow bench or shelf along each side near the front, while projections and indentations alternated from front to rear. There were numerous small holes and crevices, enlargements of seams and joints by percolating water at an early stage in the cave's history. These furnish homes for various wild animals, and nearly all of them contain bones, sticks, and trash taken in by ground hogs and wood rats which seem to find much pleasure in carrying such things from place to place.

The work of excavation began at the extreme front of the cave, where the original bottom, a mixture of sand, clay, and chert gravel, had been exposed through removal of the ashes by winds and driving rain. Almost immediately rocks, large and small, fallen from walls and roof, were encountered and interfered greatly with the digging. In the upper foot of the clay were streaks of sand and ashes, among which a mussel shell and a flint chip were found; and the top of the clay was quite uneven, appearing as if carried and thrown here, as perhaps some of it was early in the occupancy of the cave, with the object of making a more even or level floor farther back. But this admixture was only superficial; below it, the material had all the appearance of a running water deposit.

A ledge extended along the east wall for 40 feet, with a width of 12 to 14 feet; at the inner end it was about 4 feet below the general level of the floor. At 8 feet below its top a second ledge projected from it, sloping toward the center, slightly for 8 feet then more rapidly for 10 feet farther, where it merged into the bedrock. Then came level, nearly smooth rock for 18 feet, to the foot of the slope of the west wall, 14 feet out from that side of the cave. This was probably the original drainage channel.

By the gradual erosion of new channels through the limestone and the consequent abandonment of old ones, subterranean drainage is continually altering its direction and force. In this way caverns may be left entirely dry, with bare floors; or may, especially if they receive the drainage of sink holes, be partially or even entirely filled with débris thus carried in. Like others, Miller's Cave has undergone such changes. It was begun by clear water; enlarged by erosion and by breaking down of walls and roof; presently clay, sand, and gravel were carried in; finally the water no longer flowed through the front, but found its way out in some other direction. In time the deposits became sufficiently dry to afford a good site for camps and for permanent occupation. There is no way of ascertaining the rate at which these changes took place; it may have required many centuries to make an appreciable difference in appearance; or, on the other hand, the transition from one stage to the next may have been rapid.

Along the foot of the ledge from the east wall the clay was only a few inches deep; farther out on the ledge, and on the projection extending from it, were layers of red sand. Occasionally a small patch of it appeared along the western side. Probably it was washed in among the last of the natural deposits.

There was considerable chert gravel mixed with the clay, making excavation as difficult and laborious as digging up an old, much-traveled macadamized highway.

The surface of the ashes sloped upward rather rapidly for a distance of 29 feet from the front. Kitchen refuse, found in them from the start, contained many mussel shells; bones, including those of bear, deer, panther, turkey, and other large fowls, tortoise, turtle, fish, and various small mammals and birds; potsherds; broken flints, with the débris of chipping work; mortars, pestles, hammers, and mullers. Near the west wall, 14 feet from the mouth, imbedded in the ashes and a foot below their surface, was a well-preserved cranium, shown in plate 17, e, f. There were no other bones, not even the lower jaw; it seems to have been thrown here and covered with the dumped ashes.

At 18 feet from the mouth the rocks became larger and so numerous as to be almost in contact, projecting above the ashes and imbedded in the clay down to bedrock; they extended for 22 feet farther in and to within 14 feet of the west wall. The clay attained its highest level at the beginning of this pile of rocks, having an elevation of 9 feet above bedrock; it became lower toward the interior, with its surface everywhere rough and irregular.

The rocks were too large to be either moved or broken up, and owing to the condition of the roof an attempt to reduce them by blasting would have been attended with great danger, so they were perforce left in place and as much as possible of the clay between and under them dug away. Beyond those near the front, others, not reaching the top, were found one after another buried in the clay; owing to their constantly increasing number, and to the inward slope of the east wall, the limits of the excavation gradually narrowed, hampering the movements of the workmen, and it was necessary to handle the earth two or even three times to get it out of the way. There was growing risk, too, of the projecting rocks splitting off or breaking out of the clay matrix. As some of them weighed several tons, the danger became too imminent, and efforts to continue along the bedrock had to cease.