The Warner Nature Center is operated by the Science Museum of Minnesota and thus has great resources. Although the interpretive center is open to the public, the trails are only available for special groups and events so this was a great chance to check it out. Our oldest had been there for snowshoing with his school last year. They have summer programs for kids but I think they fill insanely fast.
Activities for this event including demonstrations on tapping a tree, collecting the sap, cooking the syrup (as the Native Americans would have done it as well as today), and ending with yummy maple syrup drizzled over ice cream.
Hands on activity: tapping a tree (not a live tree of course)