Police say the victim -- a man in his 20s -- had to be airlifted to a hospital. Officers from Solano County, Vallejo and the CHP were called in Friday night to control a crowd of hundreds leaving the Chardonnay Golf Course.
People attending the party say it was a birthday party and a spring break party. They say the scene was chaotic.
Police were initially outnumbered but when extra officers arrived, the crowd quickly left.