USA Junior Olympic Girls Faspitch Softball Tournament. The 2019 Avalanche Rumble will be held June 1 & 2 for fastpitch softball teams 10U through 18U. The tournament featuring 70 teams from the MT, Canada and throughout the Northwest will be held at Fort Missoula Softball Complex, Clawson Fields, McCormick Park & Big Sky High School fields in Missoula. No gate fees. Saturday teams will play three pool games to be seeded into Sunday's Championship bracket play