http://www.pbs.org/lewisandclark/index.html
http://lewisandclarkjournals.unl.edu/
http://www.mrb-lewisandclarkcenter.org/index.html
http://www.time.com/time/2002/lewis_clark/index.html
http://www.lewisandclarkidaho.org/
http://www.nationalgeographic.com/features/97/west/
http://lcweb.loc.gov/exhibits/treasures/trr001.html