Cartographically reconstructing surveys of community land grants in New Mexico to support historical research and political discourse

Cartographic visualization of past changes in ownership and management of real estate provides a basis for historical research, decision-making, and political discourse. Surveys associated with land title deeds represent unique and legally valid geographic records of historical boundaries, including those of some Spanish-Mexican land grants in the American Southwest that are currently administrative subdivisions of state. Accurate representation of land grant boundaries that were surveyed during the nineteenth century is problematic due to imprecise instrumentation, error of record, and uncertainty in landmark location. This study assesses the utility of coordinate points from US Bureau of Land Management (BLM) “brass-cap” monuments (cadastral points) for cartographic reconstruction of three New Mexico land grant surveys that exhibit distinct geographic characteristics. Findings reveal discrepancies with respect to land ownership maps produced by the BLM and provide insight to decisions made during surveying. These reconstructed boundaries are also compared to boundary maps produced by the BLM, based on comparisons with the original surveys and relative to known boundary markers. This study highlights the practical importance and potential scholarly applications of reconstructing geographic boundaries of politically active community land grants in a contemporary context.