Phelps Mill, originally called Maine Roller Mills, was built in 1889 by William E. Thomas and Ezra P. Adams on 37 acres along the Otter Tail River in Maine Township, and its success shaped the identity and economy of the surrounding town. The 36-by-30-foot mill was constructed without a preliminary sketch, with chief carpenter Royal Powers fitting each piece of lumber precisely, while Thomas and Adams also built a nearby dam to supply water power. Machinery costing $5,000 was installed in October 1889, wheat grinding began in December, and the mill produced 60 to 75 barrels of flour daily. A three-story addition in 1895 expanded production to feed, buckwheat, and rye. Farmers hauled grain from 30 to 35 miles away and often stayed overnight in Thomas's bunkhouse, known as the Farmer's Roost, where hay was added when the cots were full. Thomas also operated a barn built in 1890 that stabled 16 teams of horses free of charge. In 1890 Carl A. Gabriel became the town's first blacksmith, serving farmers and repairing mill equipment until changing technology reduced demand and he closed around 1912. The area's first store opened in November 1890 in a vacant cabin as James Morton and Company; Enos Leeper bought the stock and built a new store in 1891 that sold food, hardware, patent machines, notions, and clothing, served as a gathering place, and functioned as the post office until Rural Free Delivery began in 1909. Because the nearest mail facility was too far away, a post office was established there in 1891, and William Thomas renamed the mill and townsite Phelps, honoring his wife's maiden name, to avoid confusion with nearby Maine village. In 1910 Peder R. Sande became store manager, and the store remained in operation under various owners until 1963. Before a refrigerator was installed in the store in 1938, Sande used the long-vacant Farmer's Roost as an icehouse, storing blocks cut from Lake Leon for sale and for preserving meats, butter, lard, and cheese. In 1900 cheesemaker Solon Hubbard began commercial cheese production after securing enough daily milk from local farmers, and the factory soon received an average of 1,500 pounds each day. A small restaurant built above the river in 1920 served lunches, pies, ice cream, and homemade bread until the mill's decline led to its closure, after which the building was moved to Fergus Falls and remodeled into a home in 1946.