Hey. Check out this website. It's for leagues, but it lists parks in Michigan with links and phone numbers. Hopefully you'll get some leads from that on where to find indoor parks near you.

BMX

IF YOU ARE LOOKING FOR A PLACE TO KEEP FROM LOSING YOUR SNAP OUT OF THE GATE, A FACILITY IN GENESEE COUNTY ON THE GENESEE COUNTY FAIR GROUNDS IS SUPPOSE TO BE SETTING UP FOR THE WINTER MONTHS.  THE INDIVIDUALS THAT WILL BE RUNNING THE TRACK WAS SUPPOSE TO BE DOING SOME EXCAVATING INSIDE THE BUILDING THIS MONTH.  THEY HAVE A  TWO MAN GATE THAT THEY ARE CONVERTING TO ACCOMODATE 4 RIDERS.  THE TRACK WAS SUPPOSE TO BE UP AND RUNNING BY NOW BUT THEY RAN INTO SOME PROBLEMS WITH CONTRACT LANGUAGE BETWEEN THE NBL AND THE COUNTY OF GENESEE.  SUPPOSEDLY, THAT HAS BEEN TAKEN CARE.  CHECK THE WEBSITE  FOR RICHFIELD PARK BMX FOR UPDATES.  THE WEB ADDRESS IS BMXRICHFIELPARK.COM.  THE TRACK DIRECTOR HAS BEEN CHECKING ON THE SITE EVERY OTHER DAY TO SEE IF ANY PROGRESS HAS BEEN MADE