Flint has it.  And it's free.

Montessori is a learning method that can be used throughout early childhood, elementary and secondary school.  Families in Flint, MI now have access to a free, public choice to for Montessori education in pre-kindergarten and elementary school through the Flint Community Schools Montessori program at Durant Tuuri Mott. 

Whether your family already knows and loves Montessori education or whether you are curious about an option for school that offers hands-on learning, and freedom of choice (within limits), this is a resource for you to learn more about Montessori education in Flint.
Apply Now to Flint's public Montessori Elementary Program - Grades Early Kindergarten-3rd
To be eligible, students must be 5 years old by December 1, 2018 and live in Genesee County.  To apply, download and fill out this application and bring it to the Centralized Enrollment Office at the Administration Building (923 E. Kearsley St.) or pick up an application to fill out there.  During the summer, the Administration Building hours are 7 am-5 pm Monday-Thursday (closed Fridays).