Several professions have large collections of Michigan people throughout the world referred to as Michigan Mafia.

Diving

Occupational Safety and Environmental Health Michigan Mafia archive

During the 1970's, the term "Michigan Mafia" was coined by the US Scientific and Recreational Instructional Diving Communities to denote an extreme measure of respect given to Lee Somers, Ph.D. Diving Safety Officer, at the University of Michigan and those that had been trained by him in the University of Michigan Scientific and Recreational Diving Programs. Although perhaps not totally politically correct by today's standards, the term is used here for historical accuracy to maintain the atmosphere of respect given by the diving community to Lee and those educated by him at the University of Michigan.

Journalism

Michigan Mafia RIP by David Weir on ex-Michigan journalists in the Bay Area:

You have to go back to 1978 to understand the story of the Michigan Mafia. A group of us Midwestern migrants started to feel comfortable enough in our adopted Bay Area to bring a bit of our culture into the local scene. Some journalist colleagues and I issued a challenge to the other media institutions in San Francisco to play us in softball.

Dirt track racing

The Michigan Mafia, Peter Starr on dirt-track racing:

For some reason Michigan has always fielded a very talented batch of dirt-track racers. Perhaps not as many as California, but undoubtedly more than any state when you consider it on a per capita, or per square mile, basis. But the group that qualified as "the Michigan Mafia" came from a very small part of Michigan, essentially within a 30-mile radius of Flint. Michigan's list of national-caliber racers is impressive. Chet Dygraff, Bart Markel, Rex Beauchamp, Corky Keener, Jay Springsteen, Ted Boody, Randy Goss, Garth Brow and Scott Parker. Among them, they have more National Championship podium finishes than all others combined.

Film

The Michigan Mafia, Chris Gore, Film Threat:

But being in LA, I'm never really homesick since so many of my pals are Michiganders. It's strange how I have lived in the Los Angeles area more than ten years, yet I still have connections with so many people from the midwest and Michigan in particular. But what's even more odd, is that they are here in LA! It seems that I am always discovering others in this business who also come from the giant mitten. Guys like John Sloss, I never would have pegged him as a Michigan boy. Or Elvis Mitchell, critic for the New York Times. I have a name for it -- I call it the Michigan Mafia. And while none of us has ever really had a meeting about how to take over Hollywood, there are certainly enough of us around to do some serious damage.