Hopper Dennis Jellison is a consulting firm that provides civil engineering, traffic engineering, land use planning, landscape architecture, project management and construction services. It has been providing professional engineering services for more 25 years. Established in 1980, the firm provides services to private and public sector clients. Located in Vancouver, Wash., it operates branch offices in Tigard, Ore., and Pasco, Wash. It offers services in various areas, including Transportation, Traffic, Utilities, land use planning, landscape architecture, site and residential development, project management and construction services. Its projects include Vancouver Conference Center & Hilton Hotel, Washington State Patrol Southwest Regional Crime Lab, Washington State School for The Blind and Davidson Avenue.