The Grindhouse

The Grindhouse operates at 712 Carbon Street in Billings, Montana. The academy provides functional martial arts training across Jiu-Jitsu, Muay Thai, boxing, and mixed martial arts for practitioners throughout the Billings area. The jiu-jitsu program is directed by head coach Will Grundhauser, who has trained and competed for more than two decades, winning world championships across multiple promotions. Grundhauser coaches both hobbyist grapplers and active combat sports competitors who represent the gym at ADCC, IBJJF, and Grappler's Quest tournaments. Training covers gi and no-gi Jiu-Jitsu, Muay Thai kickboxing, boxing combinations, and cage MMA. Classes accommodate all age groups, featuring youth programs for ages 4 to 14, adult fundamental sessions, and scheduled open mat training. New students can register through the gym website to participate in a complimentary trial class.