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  • 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

    The commissioners welcome your comments, questions and suggestions. You can email all three with the address above, or the individual commissioners with the address below.

    To Be Appointed, Commissioner District One


    Casey Tighe, Commissioner District Two


    Donald Rosier, Commissioner District Three


  • Donald Rosier Biography

    Jefferson County Commissioner, District Three


    Commissioner Donald RosierDonald Rosier was elected Jefferson County Commissioner (District 3) in November 2010 and was sworn in on January 11, 2011.

    He serves on the following boards and commissions:

    • Boundary Control Commission
    • Colorado Counties, Inc. Legislative Committee
    • C-470 Corridor Coalition
    • Denver Regional Council of Governments (DRCOG)
    • DRCOG Administrative Board
    • Jefferson County Economic Development Corporation Executive Committee
    • Jefferson County Economic Development Corporation Board
    • Jefferson Parkway Public Highway Authority Board - chair pro tem
    • Noxious Weed Advisory Board
    • Criminal Justice Coordinating Committee – alternate
    • Jefferson County Transportation Action and Advocacy Group (JEFFTAAG) – chair pro tem
    • I-70 Mountain Coalition - alternate
    • CCI Public Lands Steering Committee
    • DRCOG Metro Vision Issues Committee


    Rosier chairs the Metro Area County Commissioners (MACC) group of Colorado Counties, Inc. (CCI), and is president of the CCI Front Range District. He also chairs CCI's Land Use and Energy 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) Environment, Energy and Land Use 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.

    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 was vice president of operations at Summit Oil Field Services and 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: 1-30-2015