Distribution of geomorphic landforms and soils along the El Camino Real de Tierra Adentro in the Socorro area: implications for trafficability and trail routing
— Brad D. Sion, Christopher J. Baish, and Janelle Bustarde

Establishment of trail systems was critical for early Euro-American discovery and expansion in North America. Despite the historical significance of these trail systems, few studies have documented the relationships between the physical landscape and the trails themselves. In particular, the spatial heterogeneity of terrain conditions and their control on trail establishment and preservation has seldom been evaluated in a quantitative manner. This study explores these themes along a segment of the El Camino Real de Tierra Adentro (ECR), one of the longest and most historic trails in the Americas. Specifically, we catalogue and assess major terrain features in the Socorro area of central New Mexico to evaluate their influence on trail routing decisions. This approach incorporates a cost-weighted trafficability analysis based on interpretations of the terrain qualities that most significantly affect mobility of large caravans common to the ECR. Our results demonstrate systematic linkages between terrain characteristics and trail routing locations. We hypothesize that this approach may have a range of future applications in evaluation of trail systems in other geographic locations, including assessment of human behavioral compo-nents of trail development or identification of trail segments and archaeological sites not previously known.