Nockamixon State Park: Old Mill Trail Professional Review and Guide
"This is an easy hike that starts out in the forest, then passes through a pleasant meadow before leading you to the site of an early nineteenth-century gristmill with its own rock dam. The dam was built to create a holding pond so that if the rushing waters of the stream ran low, water from the pond could be released to keep the gristmill up and running. You will also see artifacts, such as the original millstone, at this site.
The Old Mill Trail is well maintained and well marked with red blazes. There are other trails in the area, mostly horse trails, that cross the hiking trails, but obviously you should ignore them. Besides, if you stop and look at these intersecting trails, you’ll see that the surface of a horse trail is rougher than a hiking trail."