The microbial community (Eucaryotes and Prokaryotes) of the soils and lakes of the Green Lakes Valley watershed (Niwot Ridge, LTER) were sequenced in the summers of 2014 and 2015. In this system, we observed that community structure showed a significant difference among water entering the lake and the lake body (surface, 3m, and 9m depths) as well as the water leaving the lake. While community structure showed large variation within the lake body and the outlet, the majority of variation in the microbial community was found between the inlet and the other 4 sampling locations. This robust spatial signal of the microbial community within the lake suggests the presence of strong niche filtering. Preliminary data also indicate a possible connection between the talus soil communities and the lake inlet community. We hypothesize that the microbial communities and assemblages of the watershed are spatially connected and can be used for demonstrating a mechanism for microbial dispersal and niche filtering.