This report is a supplement to earlier preconstruction studies of benthic invertebrates and water quality at selected sites along the trans-Alaska pipeline corridor. Some of the problems which arose during the course of data collection and analysis are discussed. Benthic invertebrate abundance and community-structure data are presented for 20 sites along the trans-Alaska pipeline for the period September 1970 to September 1972. In addition, a list of invertebrate taxa identified to various taxonomic levels is given for 42 sites along the pipeline. (See also W74-08369) (Woodard-USGS)