(Tillamook, OR) -- The Tillamook Creamery Association will open an ice cream manufacturing plant in Decatur, Illinois next year. The plant will make Tillamook family-size and food service size ice cream for distribution in the eastern U.S. Tillamook currently has two plants in Oregon, in Tillamook and Boardman. The new plant in Decatur will use the same facility as a previous ice cream manufacturer that closed. Tillamook's ice cream sales in the eastern U.S. have grown 60-percent over the last year.