The Eel River Headwaters Restoration Project located in Plymouth, Massachusetts converted a former cranberry cultivation operation into 1.5 miles of headwater stream and 40 acres of wetland habitat in the spring of 2010. A process-based approach was used in the design and construction of the new stream, taking into consideration the ecosystem processes on a spatial and temporal scale. The restoration project is a landmark effort in converting decommissioned cranberry bogs to functioning aquatic and wetland ecosystems in Massachusetts. The goal of this study is to conduct fish and macroinvertebrate biomonitoring at the Eel River headwaters to track the establishment of resident aquatic biota, specifically benthic macroinvertebrates and freshwater fish. Fish and macroinvertebrates were collected in September 2010 at the restored Eel River headwaters (West Branch) reach, at an abandoned cranberry bog (Tidmarsh Farms, Beaver Dam Brook) reach, and at a reference stream (Eel River East Branch) reach following USEPA Rapid Bioassessment Protocols. Fish sampling followed a three-pass depletion method and macroinvertebrates were collected from 20 dip net jabs. Preliminary results from the September 2010 sampling for both macroinvertebrates and fish will be presented including taxa richness, abundance, and diversity as well as biotic indices computed from processed samples. We expect to observe a difference in fish and macroinvertebrate metrics among the three sites, with the Eel River restoration reach more resembling the reference reach than the abandoned cranberry bog reach. Our results also will allow us to evaluate the early stages of biotic development at the restored Eel River headwaters in order to assess the efficacy of such restoration projects. A second round of fish and macroinvertebrate sampling is planned for early Summer 2011.