Distribution of Terrapene nelsoni
in Mexico in the states of Chihuahua, Jalisco, Nayarit, Sinaloa, and Sonora (state boundaries in yellow). Southern (T. n. nelsoni) and Northern (T. n. klauberi) subspecies apparently delimited somewhere in the vicinity of the dotted black line. Red dots = museum and literature occurrence records of native populations based on Iverson (1992), plus more recent and authors’ data; green shading = projected native distribution based on GIS-defined hydrologic unit compartments (HUCs) constructed around verified localities and then adding HUCs that connect known point localities in the same watershed or physiographic region, and similar habitats and elevations as verified HUCs (Buhlmann et al. 2009), and adjusted based on authors’ data.