According to FINCEN, there is only about

- 204 MSBs in Detroit, MI

- 154 in the entire state of Wyoming

According to the Web site, their database contains data on 24,388 registered MSBs.

seems low. Thats an average of less than 500 per state.

To register a MSB, you can find links on the page here

https://www.fincen.gov/msb-state-selector

On the left side, there is a quick links section for "How do I register my MSB".

This returns the following PDF: https://www.fincen.gov/sites/default/files/shared/FAQ_E-Filing_RMSB_Outreach.pdf

Which in turn contains links to register. Which are of course... broken.

If you're lucky, you'll discover this link https://bsaefiling.fincen.treas.gov/main.html

It takes some digging to sort out how to register a MSB. Eventually may come upon these instructions

https://www.fincen.gov/sites/default/files/shared/FinCENRMSB_ElectronicFilingInstructions.pdf