Drilling, Nancy E., Robert A. Sparks, Brittany J. Woiderski, and Jason P. Beason. 2016. South Dakota Breeding Bird Atlas II: Final Report. Technical Report M-SDBBA2-07. Brighton, CO: Rocky Mountain Bird Observatory. http://gfp.sd.gov/images/WebMaps/Viewer/WAP/Website/SWGSummaries/SDBBA2 Final Report T-41-R.pdf