I guess you got your answer already. Yes, park is open all around year. Some roads may be seasonal though.
The park is open year round. Though there may not be an attendant at the gate or the welcome center may be closed. People can still visit the park. I believe the state of Michigan will still appreciate having a park pass. I have visited in February and other than the snowed in parking lot it was completely accessable. Enjoy your visit.
Open all year 8am 6pm fall hours
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