He was playing poker in a Deadwood saloon when he was shot dead by Jack McCall in 1876
[DOC] [TLE] John "Jack" McCall | Murderpedia, the encyclopedia of murderers [PAR] By 1876 he was living in a gold mining camp called Deadwood, South Dakota, ... 
brag, at length, about the details of how he had killed Hickok in a fair gunfight.