How gut capacity and digesta loads vary with unpredictable forage quality and abundance has not been examined in ruminants. Odocoileus virginianus (White-tailed Deer) should have greater rumen-reticulum capacity during drought years to accommodate heavier digesta loads due to diets that contain a greater fraction of indigestible material. In contrast, in years with above-average precipitation, digesta loads should be lighter due to a greater fraction of digestible material in the diet which would result in less need for a large rumen-reticulum capacity. Data were collected from White-tailed Deer obtained during October, 2006–2008, from a 214-ha enclosure at the Mason Mountain Wildlife Management Area, Mason County, TX. Digesta load, liver weights (used as a proxy to indicate metabolic workload), empty rumen-reticulum organ weights, and rumen-reticulum volume were measured. Findings, adjusted for body weight, indicated that in the year with above-average precipitation, liver weights and rumen-reticulum capacity were less than in drought years. Although the influence of year on rumen-reticulum organ weight, adjusted for body weight, was not statistically significant, graphical representation did show a trend that followed yearly precipitation. Digesta loads, adjusted for body weight, progressively increased over the study, which did not coincide with changes in precipitation. Overall, this study provided information on how rumen-reticulum attributes change with environmental heterogeneity across years.