Headquarters. Omaha, Neb.

Branch Offices. HDR has more than 70 offices in all 50 states and in 40 countries.

Roots. H.H. Henningson founded the Henningson Engineering Co. in 1917 to help develop water and sewer systems for new cities and towns throughout the Midwest.

Areas of Expertise. HDR provides architecture, engineering, and consulting services like design/build, program management, and sustainable design.

Key Markets. Federal, health-care, interiors, international, justice, science and technology, security operations, transportation, and water/wastewater.