Mode of access: Internet from the USGS web site. Address as of 2/7/08: http://geopubs.wr.usgs.gov/open-file/of01-332/of01-332.pdf; current access via PURL.
Note
Title from HTML title screen (viewed Mar. 18, 2002).
"Chronological summary by C. Heliker & D. Sherrod"--PDF title screen.