The league got its start when American investors made a deal with the Thunder Bay Junior A Hockey League, changing the league's name to the Thunder Bay-Minnesota League in 1971-72 and admitting a single American team. In 1972, the league changed its name to the Can-AM Junior Hockey League, which still ran under the jurisdiction of the Canadian Amateur Hockey Association.
In 1973, the core of the teams broke away from the CAHA and started a new league called the Midwest Junior Hockey League. It would feature all American teams, except for the first year where it still had the CAHA-affiliated Thunder Bay Hurricanes.
By the late 1970s, the league merged with the United States Hockey League. This move turned the USHL from a Semi-Professional league to what would be USA Hockey's premier Junior hockey league within a handful of years.
|Fargo-Moorhead Sugar Kings||Fargo, North Dakota||John E. Carlson Coliseum||1973-1975||fold|
|Minnesota Jr. Stars||Bloomington, Minnesota||Bloomington Ice Garden||1973-1975||renamed Bloomington Jr. Stars|
|St. Cloud Jr. Blues||St. Cloud, Minnesota||1973-1975||fold|
|St. Paul Vulcans||St. Paul, Minnesota||Ed Saugestad Rink||1973-1977||join United States Hockey League|
|Thunder Bay Hurricanes||Thunder Bay, Ontario||Fort William Gardens||1973-1974||join Thunder Bay Junior Hockey League|
|Austin Mavericks||Austin, Minnesota||Riverside Arena||1974-1977||join United States Hockey League|
|Bloomington Jr. Stars||Bloomington, Minnesota||Bloomington Ice Garden||1975-1977||join United States Hockey League|
|Hennepin Nordiques||New Hope, Minnesota||New Hope Ice Arena||1975-1977||suspend operations for 1977 to 1979; join United States Hockey League for 1979-80 season|