Trying to think of things kids like.... atv riding, fishing stuff, learning survival stuff like shelter (forts), fire stating (safely of course), casting, cooking... even if it's hotdogs over a fire, making a still for water, tree identification, animal and/or animal track i.d., trapping, pan-fishing, canoeing, climbing rocks or rock wall, ropes courses, fishing lure making.
Sling shot stuff is cool, set up targets and have contest of some sort?
Check with Capra's in Blaine. They're good people.
