The study looked at how gravel moves in fast mountain streams to help design better channels. They did experiments in a controlled flume with different slopes and gravel sizes. They found that step-pool bedforms are common in these streams. They also created a new formula to predict step height based on gravel size, water depth, and flow speed. The spacing between steps depends on their height and the slope of the stream. They also figured out how much resistance the water faces from the bedforms and individual gravel particles.