This is the only naturally occurring rapid on the Monocacy. Greenfield rapid consists of several small drops interspersed with boulders and bedrock outcroppings. At lower levels your path will be defined by these obstacles while higher levels result in a much more fun experience. Some maneuvering between drops is necessary, but there are enough eddies and short pools between to allow even novice paddlers to make the right moves. This are can collect wood, especially near the islands in the middle of the section. River left around the first island is an easier route should newcomers get nervous. At the bottom of the fall line, the old Park Mills Road bridge pier and abutments are visible and mark that you are approaching the take-out. At good levels this rapid is a solid Class II. At lower levels it's a 1+/II-