Water gushing out of Grimes Glen was dammed at the mouth of the glen and directed into a wooden raceway that carried it to mills throughout Naples, including Naples Mill along the route now named Race Street. To grind grain into flour, massive millstones were turned against each other using water power, with grain fed through the center of the top stone to a space between the stones, grooves channeling the grindings to the outside edge for collection before the grain was sorted, packaged, and shipped. A depression in the ground near the parking area marks where a mill pond was located, and the pond and raceway created the water height required to flow over the top of the waterwheels that powered the mills. A map of Naples in 1859 shows the raceway winding from the glen through the community and serving several mills, and its water was also used by the community for fire protection and everyday needs for more than 125 years. Naples Mill was built here in 1850 on the site of an earlier mill, the raceway is long gone though the mill building still stands, and the mill's power source was upgraded over the years from a waterwheel to a turbine, then a steam engine, and then electric power in 1909; the raceway was abandoned in 1921.