From the Maine Turnpike:

Take Exit 8 (Portland/Westbrook)
After paying your toll, proceed to the traffic light and turn right.
You should see signs for Route 302 as you turn right.
Turn left on Route 302 (about one mile from toll plaza).
Proceed west on Route 302 through North Windham to Naples (about 25 miles).
Turn right on Route 35 at Naples towards Harrison.
Proceed north on Route 35 about nine miles to the entrance of Camp Owatonna (on your left).

From the North Conway area:

Take Route 302 east towards Fryeburg, Maine.
Stay on Route 302 east to Bridgton, Maine.
In Bridgton, turn left onto Route 117 towards Harrison.
In Harrison, bear right onto Route 35 south.
Proceed south on Route 35 about two miles to the entrance of Camp Owatonna (on your right).