In the playoffs, after the league champions were determined, the winner of the NWOJHL would face the champion of the Thunder Bay Junior A Hockey League for the right to move on in the Memorial Cup playoffs.
The NWOJHL shared many centres with the North Shore Intermediate Hockey League which competed for the Hardy Cup.
It is possible that the NWOJHL became the Thunder Bay Junior B Hockey League in 1970, as it had many of the same teams.
The TBJBHL lasted until 1977 when Junior hockey in Thunder Bay all but collapsed.
It migrated Eastward and became the North Shore Junior B Hockey League.