The DNR is a principle department within the executive branch of Michigan government. See, MCL 324.501 et seq.. As such, it has authority to both interpret statutes and to promulgate rules and regulations pursuant to such statutes. See, Administrative Procedures Act (APA) MCL 24.201 et seq.. The head of the DNR is the Director, who serves at the pleasure of the Governor. There is also a natural resources commission whose Chairperson is appointed by the Governor and whose responsibilities include advising the Director. MCL 324.99921.
The current organizational chart of the DNR can be found here: https://www.michigan.gov/documents/dnr/EXEC_ORG_CHART_PA370_643057_7.pdf
The current members of the natural resources commission can be found here: https://www.michigan.gov/dnr/0,4570,7-350-79137_79763_79909_83509-26986–,00.html