The Grass River Natural Area has about a mile of board walk trails that loop through cedar swamp and to viewing platforms that overlook the Grass River and Clam lake.  Another four miles of trails loop through aspen and maple forest.  The upland trails are groomed for cross country skiing when there is enough snow.  Many people ski or snowshoe on the board walk trails in the winter, too, even though the trails are not really made for it.  All of the trails have little signs along them to identify the wildflowers.  Most flowers are in bloom in the summer.  Some are rare.  There is an old cabin at the preserve that is used for classes.  They have a new web address:  This link should work.