Powder Mill Creek is a small creek that runs through the west side of Bessemer and drains a few tiny swamps before merging into the more impressive Black River. Before that merge, though, it has to run past Big Powderhorn and the rugged volcanic rocks near it. Here the tiny creek makes a two-tiered drop, with the lower half being an impressive ten feet or more, over hard black rock.
Head north on Route 511 (Powderhorn Road) from US-2, driving less than 2 miles before pulling off to the right at the old lodge. Park in the lot and walk back up the road a few hundred yards until you see a trail heading to the left, which should be around the third telephone pole. If you pass by a driveway on the left side you've gone too far. Follow the trail a short distance into the woods until you hear the falls. The trail leads right to the top of the main drop, with a rope helping reach the bottom half on the left and a gentle slope to the right leading to the top half.