The Cave Falls Run on the Falls River in Idaho is a challenging Class IV-V river run, with plenty of obstacles to navigate, including tight slots, large drops, and steep rapids. This section of water is best run in late spring or early summer when the water levels are high, with a recommended CFS of 1000-2000 for a thrilling ride. This is not a run for beginner or intermediate paddlers, as the currents are powerful and unpredictable, but experienced rafters and kayakers will find plenty of excitement and thrills on this challenging stretch of river.