During the 1960s, the WHL moved into a number of large west coast markets including Los Angeles and San Francisco.

[3] In the 1965–66 and 1967–68 seasons, the WHL played an interlocking schedule with the American Hockey League.

Fears that the WHL (or a WHL/AHL merger) could become a rival major league was among the factors that finally convinced the NHL to expand for the 1967–68 season.

The NHL and World Hockey Association had moved into many of its traditional markets, and the talent pool had become strained by the fast growth in the number of professional teams.

The championship trophy of the WHL was the Lester Patrick Cup, which is currently on display at the Hockey Hall of Fame.