If you plan on using the Cedar River launch you should make sure you read this. There are some rules you will have to follow.
http://www.michigan.gov/documents/dnr/03LUOD2012_RecPass_SFC_Trails_APVD_379299_7.pdf
Has there been any acitivity for brown trout fishing out in front of the cedar river? I would expect the few browns that are left would be out there due to the early spring weather.