Between 1799 and 1846, the territory which now comprises the State of Indiana was divided by the United States public land survey into six-mile-square townships as a prerequisite for the equitable distribution of public lands. Each township, in turn, was subdivided into 36 sections one-mile square. Section and quarter-section corners, as well as a number of intermediate points, were marked by blazing trees. The location, name, and diameter of more than 214,500 "witness trees," composed of more than 80 species and generic groups, were recorded in the Indiana surveyors' journals. These journals and the maps compiled from them, records inscribed before a tidal wave of settlers swept away much of the natural vegetation of the State, represent our most tangible account of Indiana's primeval forests. They are the source of data for this study.