The Mini Mountain Challenge goes down this July 26, 2026 at Sunday River. Five hundred of the toughest and gnarliest kiddos from ages 4-12 take to the mountain obstacle course. The Mini Mountain Challenge is a scaled-down version of the Tough Mountain Challenge designed for kids ages 4 to 12 that's all about having fun and getting dirty. Kids can expect a short course that includes uphill and downhill running, dirt, mud, fun obstacles, snow guns, ball pits, foam finishes and even a few of the adult obstacles. Mini Mountain is organized into heats broken down by age group. Course length and obstacles will vary by these age group, and everything is located in the same venue as the full Tough Mountain event.