http://schools.gorge.net/hrcsd/westside/4mplateauerin.htm
http://www.nps.gov/archive/whmi/educate/ortrtg/2or2.htm
http://www.scsc.k12.ar.us/2002Outwest/NaturalHistory/Projects/LachowskyR/Plateau%20culture%20area.htm
Tribes by region:
http://memory.loc.gov/ammem/award98/ienhtml/tribes.html#pu