Sawmills cut logs into rough boards, which were then planed and smoothed into finished lumber. The remains of the planing-mill powerhouse include a square stone that once supported a 50-horsepower steam engine fueled by wood shavings. A nearby depression was used to kiln-dry freshly planed lumber to prevent warping. For years, lumber had been left outside to dry, but kiln-drying, which became widely used in Minnesota in the latter part of the 19th century, sped up the process and greatly improved the product. Before steam-power planers were perfected in the 1870s, smoothing boards was done with hand planes. In 1888, the mill reopened under the management of the Anderson and O'Brien Company with four power planers and a siding mill.