The Secesh to Main the Canyon river run in Idaho is a challenging Class III-IV whitewater experience that is best tackled in late spring to early summer (May-June) when the water flow is between 2,000-5,000 cfs. The run is characterized by steep drops, tight bends, and numerous boulder gardens that require skilled maneuvering. The most challenging section is the Big Mallard Rapid, which can be dangerous at high water levels. Other notable rapids include the Squeeze, Staircase, and Devil's Tooth. Overall, this river run is recommended for experienced kayakers and rafters with strong technical skills and an appetite for adventure.