Mound 55 – Murdoch Mound

Known as the Murdock Mound, Mound 55 was still standing in 1940 and is shown on the plat map for the area made by a local engineer. It was to be leveled for the construction of houses so a WPA crew under the direction of Harriet Smith examined the area from June 11 to December 14, 1941 (Smith 1941, 1969).

Patrick’s indications are that this was a small, conical mound, but he does not give a height. Various maps give the following heights: McAdams Map (1882), 15 feet (4.6 meters); Thomas Map (1894), 10 feet (3.05 meters); Peterson-McAdams Map (1906), 8 feet (2.4 meters). Smith, in her 1942 summary, describes Mound 55 as an oval 9 feet (2.7 meters) in height and 150 feet (45.7 meters) by 135 feet (41.15 meters) in base dimensions.

This is one of the most interesting sets of data indicating the deflation of a mound by cultivation. The Goddard air photos of 1922 show this mound in a cultivated field. Mounds 50 and 54 to the north were apparently almost completely destroyed by cultivation by the time these photos were taken. If the heights listed above can be taken as representative of the changes in Mound 55 through time, it is probable that destruction of this mound by plowing took place in the late nineteenth century. Harriet Smith’s profile drawings from her 1941 excavations show considerable disturbed or redeposited sediments spread out around the base of the mound. This is probably the result of cultivation. The difference in form as shown by Patrick (conical) and described by Smith (oval with the longest dimension north to south) is also probably the result of plowing. We can conclude that in the 1870s the Murdock Mound was a conical mound perhaps 15 to 20 feet (4.6 to 6.1 meters) in height. This is very probably its original form.

Thanks to Harriet Smith’s detailed work, this is one of the most completely excavated and examined mounds at the Cahokia site (Smith 1941, 1969). In all, 13 stratigraphic levels were determined, five in a village or habitation area below the mound and eight in the pyramid or mound structure itself.

It is Harriet Smith’s interpretation that the Murdock Mound was built as a double-terraced mound with a lower platform extending across the west face; a higher platform, which she labels the Temple Platform, was on the east half of the mound. She suggests that the northeast and southeast corners of the mound were faceted.

The basal outline of the mound, including the faceted northwest and southwest corners, was found in the excavations. Only a few feet of the height of the mound slopes were actually uncovered. The upper portions had been presumably destroyed by cultivation of the area over several decades. Smith’s reconstructions of both the terracing of the mound and its total height were based upon her projections of the slopes and faceted corners and her interpretation of ancient Cahokia engineering principles. On this basis, she projects a height for the west-facing terrace of 16.5 feet (5 meters). The eastern half, or projected Temple Platform, she proposes was 33 feet (10.1 meters) in height. The higher estimate is not consistent with the earlier figures for the pre-cultivation height of the mound, but the height proposed for the western portion, 16.5 feet (5 meters), is very nearly identical to the earliest (1882) value of 15 feet (4.6 meters). Mound 55 was built primarily of a black gumbo which made a very compact and stable mound. When the mound was abandoned, materials from the upper levels eroded down, and it was from some of this wash material that a radiocarbon date of A.D.1350 i 75 was determined (M-1290). Smith interprets this as dating the time of the latest utilization of Mound 55.

Mound 54

Mound 54 is indicated by a slight elevation in the subdivision southeast of Monks Mound. Patrick shows this mound almost equal in size to Mound 50 and part of the line of Mounds 51, 50,54, and 55. McAdams (1882) gives a height of 10 feet (3.05 meters), while Thomas (1894) indicates 8 feet (2.4 meters), and Peterson-McAdams (1906) only 5 feet (1.5 meters). By 1940, when excavations were carried out in Mound 55 just to the south and the map made for the subdivision, Mound 54 was so low that it was not noted on the land-survey map.

There is no direct reference to excavation in Mound 54, but apparently Moorehead did test in this vicinity and perhaps in the mound as well. In his earlier reports, Moorehead mistakenly numbered this Mound 74 but used Patrick’s original designation, Mound 54, in the later publication. In 1923 he noted:

This fall, the survey did not sink additional pits, but on Mrs. Tippetts’ estate, south of Monks, and on the adjoining property owned by Mr. Cole, and Mr. Wells, much work was done. Mr. Allen had leased land of Mr. Wells and he permitted us to work extensively with eight or ten men on an area lying 100 to 200 yards south of Mound 51. Here the village debris was as heavy as at any point on the Ramey lands. There were several low mounds (74, Mound 54, 75 [Mound 50], and 55). In Number 75 [Mound 50] much burnt clay was discovered, also lumps in which were impressions of reeds and sticks doubtless the walls of dwellings. [Moorehead 1923: 39]

Mound 53

Mound 53 is the southernmost of a row of what were probably conical mounds. The row, which runs north to south, includes Mounds 29, 28, and 53. McAdams (1882) indicates that Mound 53 was 20 feet (6.1 meters) high, while Peterson-McAdams (1906) shows a height of 10 feet (3.05 meters). There is no indication of Mound 53 on the 1966 UWM Map because the area on the south side of Highway 40 has been built up into residential and commercial properties. There is no indication that excavations were conducted in this mound, although Moorehead refers to it in reference to excavations in the vicinity. A slightly higher elevation with a contemporary building on it may be the location of Mound 53.

Mound 52

Elongate in form, Mound 52 is shown by Patrick to be parallel-sided with rounded ends and, on the basis of the shading, not of great height. However, the McAdams Map of 1882 gives a height of 15 feet (4.6 meters) and the Peterson McAdams Map of 1906, 8 feet (2.4 meters). Using the 127-meter (416.7-foot) contour as the base elevation, the 1966 UWM Map shows a north-south dimension of 99 meters (324.8 feet) and an east-west dimension of 83 meters (272.3 feet). However, by 1966 the mound had been greatly disturbed and partially leveled for the construction of a trailer park. Today the mound is only a high elevation in the midst of this trailer park just to the south of Highway 40. It appears, however, that much of the mound is still buried; details of its shape and nature could be determined by excavation.

There are some indications that Moorehead excavated in this mound, as he reported in 1929:

Mound No. 52, a low structure, appeared to be a house site, and during excavation we observed many lumps of hard burnt clay in which were impressions of reeds and sticks. These gave us information with reference to the walls or methods of construction of the dwellings. Cane, the favorite material used in clay or mud in building wigwam walls in the South, does not occur on Cahokia Creek, so other growths more-or-less cane-like in character were employed by the Indians. [Moorehead 1929: 31-32]

There are no other details of this excavation. Moorehead does say, however, that they did considerable work in the vicinity of this mound. One assumes this was the excavation in the so-called village site area that he marked on his 1929 map.

Mound 51

Although almost totally destroyed, Mound 51— known locally as the Persimmon Mound—is one of the better recorded mounds at the Cahokia site. Patrick illustrated it as an oval-shaped mound with an east-west axis somewhat longer than the north-south. Moorehead maintains this representation in his various interpretations of the Patrick Map. The 1966 UWM Map was made after the mound had been largely destroyed and spread out, so it shows little of the mound’s nature. The mound apparently was still in good shape in the early 1920s when it was photographed by Goddard. It appears on this photo as a well-defined mound with an oval base and a flat top.

There are several contour maps of Mound 51, the first made in 1940 when a survey was made of a subdivision southeast of Monks Mound. The contours on that map are unlabeled and appear to have been sketched in rather than surveyed in detail, but they do show the mound much as it appears in the photograph taken in 1922. This map shows the mound to be approximately 160 feet (48.8 meters) east-west and 140 feet (42.7 meters) northsouth.

On the USGS map the base elevation for that area is a contour line of 420 feet (128.0 meters) above sea level, and the mound is outlined by the 430-foot (131.1-meter)contour. This suggests that at the time the USGS map was made the mound was more than 10 feet (3.05 meters) high. The USGS compilation drawings show this mound in much greater detail than the published quadrangle sheet. A base contour of 420 feet (128 meters) encompasses both Mound 50 and 51. The top of Mound 51 is encircled by the 430-foot (131.1-meter) line, indicating Mound 51 was at least 15 feet (4.6 meters) high at that time. The largest of the earlier estimates, on the Thomas Map of 1894, is 20 feet (6.1 meters).

If we assume a height of more than 15 feet (4.6 meters), it seems probable that the contour lines on the 1940 map represent a 3-foot (0.9-meter) contour interval. It is likely that this is the contour interval represented since land surveyors often used surveying rods divided into yards rather than feet. Certainly, the map probably doesn’t show 5-foot (1.5-meter) contour intervals, the standard practice in topographic surveys, as this would make the top of the mound at least 25 feet (7.6 meters) above the lowest contour line.

During the salvage excavations conducted by Charles Bareis in 1967, a contour map was made of a portion of the mound. From this contours were projected for the total mound as it existed at that time. The datum reference was the top of the mound; it was assigned a value of 100 feet(30.5 meters). The lowest contour mapped was 83 feet (25.3 meters). This indicates a height of about 17 feet (5.2 meters) for Mound 51 in 1967. This corresponds favorably with data from the other maps. The mound apparently retained this shape until the 1960s. At that time it was leveled and the mound soil used for fill. Little (a few feet) of the mound remains.

If Mound 51 is the vantage from which Wild’s drawing was made, he is the first to report archaeological data for this mound. Wild apparently did not conduct any excavations but “picked up about a half a peck of broken bones and pieces of pottery and flint” (Wild 1841: 52-53) from the surface. This litter on the surface of mounds is similar to Brackenridge’s descriptions, three decades earlier, of the ubiquity of archaeological materials over the surface of the entire site. Post1840s cultivation of the area has wiped out this aspect of Cahokia as well as the forms of the mounds.

Charles Bareis and others, who were conducting nearby highway salvage archaeological work, made test excavations in the mound and below the surface before it was leveled. First, a 60-foot-long, 10-footwide trench (18.3 by 3.05 meters) was made across the top of the mound. It was excavated to a depth of about 5 feet (1.5 meters). The testing suggested that the mound had been constructed in at least two stages, and much of the fill for the mound was a sandy type soil (Bareis 1962: 8). As the mound was further leveled, Bareis worked with crews from the University of Illinois Field School, of which he was director. Portions of the data recovered from those excavations have been reported by William Chmurny in his doctoral thesis (1973).

One can say with assurance only that Mound 51 was built in at least two stages with some evidence of specialized utilization indicated by fire pits on the surfaces of each stage. An interesting feature was discovered below the mound a large borrow pit from which earth was taken for mound construction; perhaps it was used for Monks Mound. This borrow pit had then been filled with trash and soil, the area leveled, and Mound 51 constructed over a portion of the former borrow pit.