Killearn Mill is situated just below the bottom of the Glen woodland. The mill is on the Kirkhouse burn. To help the flow of water through the Glen parts of the stream was canalized. Above the mill, water flowed into a mill dammed mill pond. A sluice controlled the flow of water down the mill lade to power a water wheel at the mill. The details can be clearly seen here on the 1896 25-inch to the mile OS map. Originally the mill was used to grind oats to make meal but it then became a sawmill, latterly powered by a steam engine. The McGowans ran the mill from 1754.
In the last century the sawmill moved to a site next to the railway which had been a sawmill for the Killearn estate. There was a siding on the railway line at this point, known as the Blackburn siding. This is the site now known as the Killearn Mill Business Park.