Thurston County, home to hundreds of salmon bearing streams, has successfully implemented a comprehensive program to replace fish blocking culverts in the county. The Thurston Board of County Commissioners directed Thurston County Public Works to develop the program after reviewing the damaging environmental impacts of fish blocking culverts and the challenges Washington State faced managing and replacing culverts on state roadways. A total of $4.5 million was budgeted from the Thurston County Real Estate Excise Tax (REET) to pay for the initial start of the program and the first project cycle (2017-2018). The foundation of the program, which resulted in the opening of more than 7.5 miles of fish habitat in 2018, was the development of a holistic process for prioritizing culvert replacement. County culverts were inventoried, cataloged and scored based upon anadromous fish access and potential habitat, barrier status, culvert condition and maintenance history. The result was a database of fish blocking culverts in Thurston County. Priority culverts were then identified, field tested, and recommended for construction based upon the highest collective return of fish habitat for the budget cycle. Of the more than 3,000 culverts in use on Thurston County roadways, engineers and environmental specialists identified 150 potential fish blocking culverts and successfully completed five projects under the Fish Passage Enhancement Program in 2018, on budget and on time. Program leads at Thurston County worked with three design engineering firms and three construction firms to complete fish passage enhancements at the five separate sites. Enhancements include the removal of eight fish-blocking culverts, installation of three prefabricated bridges and completion of two large fish-passable culverts. Riparian areas and streambeds were also enhanced at each project site to improve fish passage. Replacement of the outdated culverts opened passable stream habitat that allows fish to spawn and rear their young in areas not available to anadromous fish for decades. Stabilizing the stream crossings also reduced erosion, improved downstream water quality and helped reduce flooding and maintenance issues associated with high flow rain events. Results of the program have been swift, with the first fish in nearly 100 years passing underneath Hunter Point Road on its way upstream in November 2018.