The objective of this study is to characterize natural clayey colluvial soils that occur in eastern Oklahoma. Three study sites were selected in areas of known landslides. Piezometers and permeability bore holes were placed in the soils in undisturbed areas adjacent to landslides. Undisturbed samples were taken for laboratory analysis. Rainfall at the sites were monitored continuously. Horizontal drains were installed to determine flow rates of subsurface water within the soils. A stability assessment of the soils is presented to demonstrate the degree of landslide hazard in these areas.