Career
In that 1961 to 1975 span, the Rams made the playoffs 5 times (1967,1969,1973,1974,1975), reaching the NFC championship game of the 1974-1975 NFL playoffs and the 1975-1976 NFL playoffs, but losing to the Minnesota Vikings and to the Dallas Cowboys, respectively. In the 1974 divisional round, the Rams defeated the Washington Redskins, as Cowan was successful against the opposing the right defensive end Verlon Biggs. In the 1975 divisional round, Doug France started in his place as the Rams defeated the Saint Louis Cardinals.
Cowan came back to play against the Cowboys, his final game, as the Rams could not get past them.
Cowan was replaced by Doug France in 1976.