The Big Ten hockey conference only consists of seven teams - Notre Dame + six of the actual Big Ten members (Michigan, Ohio State, Penn State, Minnesota, Wisconsin, Michigan State). Notre Dame, Michigan, and Ohio State made the frozen four. The other team in the frozen four - Minnesota-Duluth, is from Big Ten territory but is in the NCHC.
60 total teams with the following conferences: Atlantic Hockey, Big Ten, ECAC, Hockey East, NCHC, and WCHA. Arizona State is the sole independent.
The WCHA was the dominant one, I think, until the Big Ten formed as a conference.