Montane riparian ecosystems have high primary productivity, serve as buffers between terrestrial and aquatic systems, and can decrease nitrogen (N) inputs to surface and groundwaters. As the ecological and economic values of riparian systems have been recognized, the understanding of multiple-use impacts (recreation, wildlife habitat, livestock grazing) has become increasingly important. Although studies of riparian ecosystems have shown the effects of large ungulates on aboveground plant dynamics, little consideration has been given to belowground soil dynamics.  Our goal was to investigate the effects of long-term cattle grazing on soil microbial functions in comparison with sites exclosed from grazing for 50 years in a montane riparian zone of north-central Colorado.  We characterized spatial and temporal variation in aboveground primary production (APP), soil microbial biomass, carbon (C) and N mineralization, and denitrification potential in both grazed and control treatments.  Nonmetric Multidimensional Scaling (NMS) revealed plant community patterns between streambank, middle-riparian, and upland edge locations.  Thus, we used grass, sedge, and forb functional groups as covariates in an ANCOVA of different response variables.  We did not find significant effects of long-term cattle grazing on nutrient processes, soil microbial biomass or APP (P > 0.1771) which suggests that cattle have a neutral effect on nitrogen cycling in this ecosystem and that montane riparian zones on public lands may be managed beneficially for multiple uses.  Although there were no significant cattle grazing effects, we found landscape variation in riparian N dynamics and APP (P < 0.0372).  Streambank locations had lower C and N mineralization, denitrification potential, and soil microbial biomass in comparison with sampling locations in the middle and upland edge of the riparian zone.  Differences between locations indicate that it might be important to stratify riparian zones by community type when considering riparian processes at regional scales.