Horizon Milling will close its Topeka mill on Friday.
A small number of employees will remain at the facility through January to remove equipment.
According to company officials, the 129-year-old mill has served the company well, but the plant couldn't compete without extensive and costly upgrades. Demolition crews will begin work on the mill in February.
Horizon will continue modernizing and expanding its key locations, including an ongoing expansion at its Newton mill. Flour customers supplied by the Topeka mill will get product from other Horizon mills.
Horizon Milling is a joint venture between CHS and Cargill.