• Contact Information

    Board of County Commissioners


    7:30 a.m.- 5:30 p.m.

    Contact Us

    100 Jefferson County Pkwy.
    Admin and Courts Facility
    Golden, CO 80419

    Libby Szabo, Commissioner District One


    Casey Tighe, Commissioner District Two


    Donald Rosier, Commissioner District Three


  • Donald Rosier Biography

    Jefferson County Commissioner, District Three


    Donald Rosier was elected Jefferson County Commissioner in November 2010 and won the re-election to another four-year term in November 2014.  

     Commissioner Donald Rosier




    He serves on the following boards and commissions:   

    • Boundary Control Commission 
    • Chatfield Watershed Authority 
    • Colorado Clean Water Coalition 
    • Criminal Justice Coordinating Committee
    • Jefferson County Economic Development Corporation Executive Committee 
    • Jefferson County Transportation Action and Advocacy Group (JEFFTAAG), Pro-Tem
    • Jefferson Parkway Public Highway Authority Board
    • Noxious Weed Board
    • Urban Renewal District
    • WestConnect Corridor Coalition

    Commissioner Rosier will serve as an alternate on the Jefferson County Economic Development Corporation Board, the I-70 Mountain Coalition, the First Judicial District Services Advisory Board, C-470 Corridor Coalition and the I-70 Mountain Coalition.

    Rosier is past chair of the Metro Area County Commissioners (MACC) group of Colorado Counties, Inc. (CCI), and is past president of the CCI Front Range District. For the past three years he has chaired CCI's Land Use and Natural Resource Steering Committee. In 2011, Rosier was named CCI’s Freshman Commissioner of the Year. CCI represents boards of county commissioners from more than 60 Colorado counties.

    Rosier also serves on the National Association of Counties (NACo) Transportation Steering Committee, which develops NACo policies and represents counties before Congress. In 2012, he was chosen to participate in a national leadership institute developed by NACo and the Cambridge Leadership Associates. He also serves as President of the National Conference of Republican County Officials (“NCRCO”).

    A graduate of Colorado State University with a bachelor’s degree in civil engineering, with an emphasis in water resources, Rosier has worked in the consulting engineering field, the public engineering sector, the land development and construction field, and he has worked in energy development and exploration.

    Before being elected county commissioner, Rosier served as president of operations for Summit Oil Field Services and as a principal with Westside Investment Partners. Previous positions include director of land development at Alliance Commercial Partners and vice president at Neumann Homes. One of his first positions included working as a review engineer with the city of Westminster.

    Rosier, a fifth-generation Coloradoan, who grew up in Arvada and has lived in Jefferson County his entire life, attended Swanson Elementary, North Arvada Junior High and Arvada Senior High School. He is active in competitive sports and played high school soccer, basketball, swimming and track.

    He and his wife, GeriAnn, have lived in south Jefferson County since 1992 and have a daughter and two sons. An active community volunteer, Rosier served as a member and chairman of the Jefferson County Community Development Advisory Board for eight years. He also teaches Sunday school, coaches lacrosse and volunteers at local schools.

    Last Updated: 1-14-2017