South Dakota Breeding Bird Atlas - Full results of the project completed in 1993, with 219 distribution maps. www.npwrc.usgs.gov/resource/distr/birds/sdatlas/sdatlas.htm
South Dakota Ornithologists' Union - News and events, meetings, count results, list of hotspots, listers' lists, programs, and forms. www.homepages.dsu.edu/palmerj/SDOU/SDOU.html
