Hi KoppKevin-7462,
As I know, Grant and Michigan have no toll-free phone numbers but have toll phone numbers. Toll (service) numbers are automatically assigned as shared audio conferencing numbers to organizations when they are enabled for Audio Conferencing.
For more information about Audio Conferencing, please refer to this article:
https://learn.microsoft.com/en-us/microsoftteams/audio-conferencing-in-office-365.