Patrick noted a small, conical mound to the west of Mound 42 and directly east of the northwest corner of Mound 44, a large, rectangular platform mound (Figures 6.2 and 6.4). Mound 43 is shown on all later maps, including the Thomas Map, Peterson McAdams Map, and a map included in Titterington’s publication on the Cahokia site. Mound 43 is indicated on the UWM Map by a loop in the 128-meter (419.9-foot) contour line; the elevation of its highest point is 128.8 meters (422.6 feet), establishing its height in 1966 as only about 0.8 meters (2.6 feet) above the surrounding area. Earlier maps give a much greater height for this mound, ranging from 8 to 10 feet (2.4 to 3.05 meters). The height of Mound 43 has decreased considerably because of modern agriculture, though Mounds 42 and 44 show less change over time.
No excavations have been conducted in Mound 43. It seems to be part of a group of mounds that includes Mound 44 just to the west and Mound 91, between Mounds 43 and 44 and to the north of the line between them. Mound 91 went unnoted by earlier investigators, and it will be discussed in Chapter 7, which describes the mounds which have been added due to 1960s research regarding the Cahokia site. Together these mounds may well form a group surrounding a plaza.