The uppermost of the five Black River Falls, Great Conglomerate Falls is also the most impressive. The river splits over a huge mound of conglomerate rock to form two separate waterfalls that are so separated that they are difficult to capture in a single shot. Boardwalks and a well-placed viewing platform make this an easy and worthwhile stop.
Head up the scenic Route 513 from Bessemer and, about 10 miles past Big Powderhorn, there will be a drive to the right for Potawatomi and Gorge Falls. Turn here and park at the parking lot. Follow the trail to the river, heading towards Potawatomi Falls, and then follow the path upstream to Great Conglomerate. At times this path may be muddy, so be prepared in wet weather.
There is a separate parking area for Great Conglomerate Falls that you'll pass before reaching Potawatomi/Gorge, though I'd recommend skipping it. The walk is about the same distance and, by stopping at the further one, you'll be able to visit three waterfalls and only have to park once.