This roller mill was made by Great Western Manufacturing in Leavenworth, Kansas. The dates on the drawings for this machine are dated 1903. This unit is a 6-20, meaning that the rollers are six inches in diameter and twenty inches long.

The grain enters the mill at the top, where the feed rate is regulated before it pours down onto the rollers. The rollers are in pairs, turning such that they pull the wheat downward in between them. The rollers rotate at different speeds, which has the effect of tearing apart the kernels of grain.

Mills of this type were originally met with scepticism by millers who had for generations used stones to reduce grain to flour. However, it was eventually learned that the roller mill is less labor intensive and is more economical.

The original building from which this mill came was a multi-level structure. Grain was elevated to the uppermost level, where it was fed into the roller mills. The grain was fed through a series of mills until it reached a lower level. There, the flour was sifted, with the sufficiently fine product being sent out for shipment, while the coarser product was sent back to the top for another trip through the mill.

Originally, this mill was driven from a line shaft that was on the level below the mill. The drive belt went straight down through the floor.