There was a circular depression approximately nine feet in diameter in the top of the mound where pothunters had been at work. Excavation revealed that the pothole had been dug to a depth of 4.8 feet and had later been partially filled by natural agencies. Unfortunately, the pothole had destroyed most of the central hearths associated with the two house floors found at the base of the mound. After the trees and bushes had been cleared from Mound C the standard grid of 5-foot squares was established with a base stake set 125 feet south and 100 feet west of the approximate center point of the mound. The initial step in excavating the mound was to dig the southwest quadrant down to elevation 100.0 feet. Next, the southeast quadrant was excavated to the same level so that an east-west profile remained standing completely across the mound. After the profile had been studied and recorded, the other two quadrants were removed and the entire mound was levelled at elevation 100.0 feet, where a circular zone of dark soil containing a large amount of charcoal marked the outline of what later proved to be the remains of two houses, one superimposed on the other. A narrow east-west trench was next dug across the house area, the north edge of the trench being on the N125 line so that it matched the bottom of the major east-west profile which had already been removed. This trench revealed two thin layers of dark midden soil, each of which represented the floor level of a house (Fig. 7). The two floor levels were separated by a layer of clean, yellow sand. The lower floor rested on undisturbed soil at the base of the mound. Numerous charred segments of poles lay in a jumble on and just above the upper floor as though the house walls had burned and collapsed. [Illustration: Fig. 6 HARROUN SITE 41 UR 10 MOUND C AREA contour interval = 0.5 feet shading indicates excavated area] The house floors were completely excavated, the artifacts and other material associated with each floor being collected and sacked separately wherever possible. Two concentric rings of post molds at the periphery of the house area were exposed and recorded, as were several interior post molds (Fig. 8). An entrance passageway was delineated at the west side of the house area. In order to determine the relationship of the mound to the floodplain several short trenches were carried from the edge of the mound out into the floodplain formation (Fig. 6). A depressed area in the surface of the floodplain between the mound and the lake was also trenched in an effort to determine whether it may have been a borrow pit. Several other trenches were dug south and west of the mound in an unfruitful search for any middens, houses, burials, or other occupational features that might have been located near the mound.