 Major manufacturers in Grand Forks include wind turbine manufacturer LM Glasfiber and small aircraft manufacturer Cirrus Design . Major food producers include potato processor J. R. Simplot Company and the state @-@ owned North Dakota Mill and Elevator which is the largest flour mill in the United States . Amazon.com and SEI Information Technologies both operate call centers in Grand Forks . Other large private employers in the city include the locally owned Alerus Financial branch of banks , Home of Economy , and the locally owned Hugo 's chain of supermarkets . 
