Mode of access: Internet at the USGS web site. Address as of 03/26/03: ftp://ftp.umesc.usgs.gov/pub/media%5Farchives/documents/reports/1991/91%5F06.pdf; current access available via PURL.
Note
Title from title screen (viewed on Mar. 26, 2003).
"July 1991."
"Environmental Management Program, Long Term Resource Monitoring Program, Upper Mississippi River System."
"This PDF file may appear different from the printed report because of slight variations incurred by electronic transmission. The substance of the report remains unchanged."