 In the 1915 – 16 season, Holmes signed with the Seattle Metropolitans of the Pacific Coast Hockey Association (PCHA), although he was still under contract to the Blueshirts. In his first season with the Metropolitans, Holmes played 18 games. He finished with a 9 – 9 record, with no shutouts and a 3.67 goals-against average. That season, the Metropolitans missed the playoffs. In his sophomore season, Holmes posted a 16 – 8 record over 24 games, with two shutouts and a 3.28 goals-against average. In the Stanley Cup finals, Holmes posted a 3 – 1 record with a 2.75 goals-against average, en route to the Metropolitans' only Stanley Cup win. The Metropolitans became the first American-based team to win the Stanley Cup.
