The Cedar River watershed is part of the water supply for the city of Seattle, and also includes habitat for threatened salmon. Important objectives for this prescription therefore included safe and secure drinking water, and conservation of important fish habitat. Pretreatment forest was a 65-year-old cohort of western hemlock (Tsuga heterophylla (Raf.) Sarg.), with densities of 200 to 400 square feet of basal area per acre. The project was designed with stakeholder involvement, including local tribes, conservation groups, oversight committees for the watershed, and local citizens. After a public involvement workshop, the project took a year to design. Public comments pushed for yarding fewer trees, creating more gaps, thinning conservatively, and not cutting big trees. In the end, 230 acres were thinned. Yarding corridors created gaps, and smaller skips and gaps were located by the operators. Operator certification was done beforehand to ensure that operators could "read the fine print," and fully understood the prescription. Only one successful bidder could implement downhill yarding. The project designers used a light model to create variability, and the Topex model to calculate topographic exposure and effect of tree position relative to gap edges on diameter growth and average crown width. They found that creating gaps had a greater effect on creating large trees than thinning.