Knife River Corporation. The company mines aggregates and markets raw construction materials including crushed stone, gravel, and sand. Other construction materials include asphalt, liquid asphalt cement, and ready-mix concrete. Knife River has operations in Alaska, Hawaii, Oregon, California, Idaho, Minnesota, Montana, North Dakota, Oregon, Texas, and Wyoming. The company also provides such integrated construction services as site development, highway construction, and wind farm construction in the central and western US, including Alaska and Hawaii. Knife River is a subsidiary of MDU Resources .