AMA Supercross, Las Vegas Race on the circuit of Sam Boyd Stadium, Las Vegas. Rounds in the Supercross Season 2017,2018,2019 and 2020. AMA Founded in America and sanctioned with the aid of the American Motorcyclist Association (AMA) in 1974. Watch the race live of AMA Supercross Round 4 Streaming anywhere on Onlinesupercross.net and full race replay