Drilling, Nancy E. 2015. North Dakota Colonial and Semi-Colonial Waterbird Inventory, 2014–2015. Final Report. Technical Report SC-NDCWB-02. Brighton, CO: Bird Conservancy of the Rockies. http://www.birdconservancy.org/wp-content/uploads/2016/01/NDColonialWaterbirds_FinalReport_2015.pdf