Black Rock Mill

Picture yourself back 80 or so years ago sitting near the old mill under the shade of a large elm tree, listening to the splashing of the water as it runs over the mill wheel and hearing the faint creaking of the wheel as it turns. The sun shines down through the leaves, making moving patterns on the water of the mill pond as a gentle breeze stirs the air.

This pleasant quiet scene is drastically turned around once you enter the mill building. You come into a large dark room. Motes of flour dust dance in shafts of light coming through the few windows. The dust is everywhere, and it gets in your hair and clothes. You cover your face with a handkerchief to avoid breathing it in. But it is not the dust that strikes you first. It is the noise. The huge stones grinding against each other create a deafening growl that shakes the floor and forces you to shout to be heard.

This is the scene you can imagine when you visit the ruins of Black Rock Mill on Black Rock Road in Germantown. The roof of the mill is gone, but the walls, made of black rock quarried just across Seneca Creek, still stand. Inside the walls are exhibits about the mill and how it worked, and a mill stone. There is also a circular saw blade, since this mill doubled as a saw mill.

On a stone in the wall is the date “1815.” This was the year that Thomas Hilleary had the mill constructed, although it did not begin operation until the following year. It was a substantial three-story stone building with the millstones on the second floor, the flour hoppers to catch the ground grain for bagging on the floor below. The bags of raw grain or corn were hoisted by pulley to the upper floor where the grain was poured down funnels, chutes and gates to guide the grain gradually between the two grinding millstones.

The millwheel was located outside on the side of the building. Water from Seneca Creek was dammed into a pond on the other side of Black Rock Road and then directed into a millrace that ran under the road and along the side of the building, then made a sharp right turn to hit the undershot millwheel  at its midpoint. The 50-yard millrace is still there today.

Black Rock Road was actually built to serve the mill, and had a bridge over Seneca Creek long before other roads in the area. This is how important mills were to the community. The grain had to be ground soon after harvesting and bad roads and swollen creeks could not be a hindrance to the farm operations. Because “all roads led to the mill” it was also a gathering place for the local community.

Thomas Hilleary died in 1844, and the mill was run by Charles Mansfield until the estate was finally settled in 1861 and the mill purchased by Nicholas Offutt. Nicholas died in 1894 and the mill was sold in 1895, but remained in operation until 1920 when a flood wiped out the dam on Seneca Creek and severely damaged the mill.

The wood sawed at Black Rock Mill was used to construct many homes and commercial buildings in Germantown. Ironically, the wood to build the Bowman Brothers steam-powered mill next to the railroad was sawed there. The new steam power spelled the end to water-powered mills.

The miller’s house was on the high ground to the west of the mill, but it caught fire in 2001. Although it was rebuilt, most of the historic part of the structure no longer exists.

In the 1970s the mill, as well as all of the land running along the creek, was purchased by the state as a part of the environmental protection plan for Seneca Creek. It is now part of Seneca Creek State Park. In 1986 the historic Black Rock Mill was leased to Montgomery County, which did the work of stabilizing the ruins and erecting interpretive signs.