When analyzing all sites together, we found the largest magnitude correlations between carbon stocks and grain size, particularly between percent silt content (ρ= 0.531, p = 9E-49) and sand content (ρ= -0.524, p = 2E-47) with positive and negative correlations, respectively (Table 4). Correlations between organic carbon stocks and location data, climate data, and elevation are weak (<0.3) but significant and suggest that carbon stocks are somewhat higher in the high elevation mountain ranges in the interior of the continent that have cooler climates.