Beavers construct structurally complex and dynamic damming networks. Beaver increase biodiversity by providing habitat for many species of waterfowl, wildlife, fish and invertebrates through dam building activities. Beaver are able to completely reshape their surroundings. In mountainous regions snow melt annually washes out the previous year beaver builds. Beaver colonies thrive by recapitulating the entire dam building process over a period of three to five months. We present a study of beaver colony damming network construction in the foothills of the Rocky Mountains in northwestern Montana. Using a combination of hydraulic measurements and aerial imagery we observed the construction activities of beaver during their active building season. To observe dam building at high enough spatial and temporal resolution we used a DJI Phantom 4 Pro drone to conduct weekly scans of four sites from May 2018 to August 2018, covering approximately 103 hectares, 17 beaver colonies responsible for the construction of 76 dams over a three month period following snow melt. We constructed high resolution (1.3 cm/px) orthomosaics which were then annotated in order to track dam network formation and growth. Results suggest that the initiation of building corresponds to the measured volumetric flow rates at each site. Beaver engage in dam building when the volumetric flow rates were between 0.2 m3/sec and 0.5 m3/sec. Beaver appear to build on existing or washed out dams before nucleating the build of new damming sites. The majority of dams were built downstream of the beaver lodge. The final damming complex is many times larger than any one individual beaver and likely taking place in many locations simultaneously.