The Cowmire Creek site encompasses a 4-hectare area within the floodplain of the Missouri River near Hazelwood, St. Louis County, Missouri. Yielding one of the largest Middle Woodland material culture assemblages excavated to date in the region, this site is situated on a narrow linear terrace near the point where Cowmire Creek exits the uplands and traverses the Missouri River bottomlands. Archaeological investigations conducted by Prairie Archaeology & Research (then known as Environmental Compliance Consultants, Inc.) during the summer and fall of 2001 resulted in the identification and complete excavation of 457 cultural features arranged in twelve defined clusters.
Based on the ceramics, radiocarbon dates, ethnobotanical remains, and lithics, it appears the human use of the Cowmire Creek locality began early during the Middle Woodland sequence circa 150 B.C. This occupation occurred primarily near the western margin of the site and resulted in several dense clusters of shallow basin-shaped pits containing transitional early and middle Havana series ceramics (Naples, Havana Cordwrapped, and Hopewell wares) and contracting-stemmed projectile points such as Norton forms.
Following this occupation, it is unclear if the use of the Cowmire Creek locale continued although markedly less intensively or if a hiatus of use spanning nearly 175 years occurred at Cowmire Creek. Whatever the circumstances during the interim, a second intensive period of use began at roughly A.D. 100 and continued over the course of 150 years or so. This second period of occupation coincided with the transition from the Middle to Late Havana phases, which is demarcated in the archaeological record by the increased prevalence of Havana Plain vessels and the introduction and increased production of Pike Rocker Stamped and Baehr Brushed vessels, the waning occurrence of Hopewell items, and the manufacture of smaller Manker-style projectile points. The latter use of the site resulted in the excavation of a series of less-densely packed shallow basin clusters distributed over a broad area of the middle and east portions of the site.
The early component at Cowmire Creek generated the earliest absolute Middle Woodland dates from the region. Archaeological investigations at the Cowmire Creek site (23SL1056) began as a result of the planned development by TRiSTAR Business Communities, Inc., of Earth City, Missouri, for the 450-acre Park 370 commercial and light industrial center, located near Hazelwood, St. Louis County, Missouri. The level of effort to complete the Cowmire Creek field investigations required more than 23,920 man-hours over a period of eight months.
The Park 370 project involved impacts to approximately 29 acres of wetlands requiring the acquisition of federal permits from the United States Army Corps of Engineers subject to Section 404 of the Clean Water Act of 1972 (33 U.S.C. 1344). The U.S. Army Corps of Engineers consulted with the Missouri Department of Natural Resources, State Historic Preservation Office, in accordance to Section 106 of the National Historic Preservation Act of 1966 (16 U.S.C. Section 470 [NHPA]) and its 12 December 2000 implementing regulations (36 CFR Part 800) to evaluate the development's impact to historic properties.