The Montreal Canadiens signed Gus Rivers as a free agent in January of 1930. He finished the season with the Habs, playing sparingly and contributing only one goal in 19 games. But he also played in six playoff games and helped the Canadiens win the Stanley Cup. He contributed one goal in the playoffs - an overtime game winner in game one of the semi-final series versus the New York Rangers.
Rivers returned in 1931-32 for his only full NHL season. Again he was used sparingly, scoring only twice and adding five assists. And again the Canadiens returned to the Stanley Cup finals and repeated as champions. Rivers played in all 10 playoff games, scoring one goal more goal.
Rivers played 25 more games in the NHL before becoming a fixture with the minor league Providence Reds. He would win another league championship there in 1937.