This report documents work completed by the Willamette Partnership between 2006-2008 under a Targeted Watershed Grant from the U.S. Environmental Protection Agency. It details the Partnership’s scientific and technical work to develop crediting protocols and market infrastructure, the market appraisal process, and work developing pilot transactions and the necessary regulatory framework. The report includes a section on ‘Lessons Learned’ and should be a useful guide to those interested in developing an ecosystem service marketplace.