- This report was derived from field data collected by personnel of the US Forest Service (USFS) and Oregon Natural Heritage Program (ONHP). The area examined encompasses four National Forests (Gifford Pinchot, Willamette, Mt. Hood, and Siuslaw) and two Bureau of Land Management Districts (Salem and Eugene). It does not include the Willamette Valley floor. Sampling focused on the Tsuga heterophylla zone, however some sites are transitional with the lower subalpine zone, reaching 5,300 feet elevation. Wetland sites with very obvious human development (e.g., dams and roads) were avoided to provide an account of relatively unmanipulated communities. However, most sites examined were peripheral to intensively managed forest and likely have been affected to some degree. A suite of field methods were employed. All potential sample sites were first identified by USFS and BLM personnel familiar with wetland distribution on their jurisdictions. Every wetland site was mapped for its association boundaries, plot locations, adjacent terrestrial vegetation, surface water, roads, etc. Based on 638 plots, eighty-seven associations were classified. Thirty associations are distinct and have not been identified previously, thus they should be considered new. An additional thirty-three associations closely match accepted associations already classified by ONHP. The remaining associations resemble ONHP types but are neither close matches or unique enough to consider as new associations.