Founded in 1917, Knife River Corporation is one of the leading aggregate producers in America. The firm makes available products, such as aggregate, asphalt, building materials, cement, liquid asphalt, rebar, masonry and ready-mix concrete. In addition, it provides construction and specialty services to public/private sector clients. The firm operates in 17 states throughout the central United States, western United States and southern United States, Alaska and Hawaii. Its list of acquisition includes Fairbanks Block and Landscape Supply, Yarbroughs Material & Construction, Amador Transit Mix and Ideal Contractors, in 2008. Knife River Corporation is a subsidiary of MDU Resources Group Inc.