Description
Item Description:Title from title screen (viewed on Sept. 11, 2008).
"April 1984."
"FWS/OBS-82/10.56."
Electronic resource.
Physical Description:vii, 43 pages : illustrations, map ; 28 cm.
Format:Mode of access: Internet from USGS web site. Address as of 9/11/08: http://www.nwrc.usgs.gov/wdb/pub/hsi/hsi-056.pdf ; current access available via PURL.
Bibliography:Includes bibliographical references (pages 37-43).