HDR is an architecture, engineering, and consulting firm based in Omaha, Nebraska. The company was founded in 1917 as Henningson Engineering Company and has since grown to become one of the largest engineering firms in the United States. HDR provides a wide range of services, including architecture, engineering, environmental consulting, and construction management. The company has worked on a number of high-profile projects, including the Hoover Dam Bypass and the San Francisco-Oakland Bay Bridge. HDR is committed to sustainability and has been recognized for its efforts in this area by organizations such as the U.S. Green Building Council.