The Northmen Site is on Naples Rd.

If you're coming in from M-66 you will need to turn on Sharon Rd and follow it to Naples Road.

If you're coming in from US-27 you will exit at the Military Road exit (North Higgins Lake State Park) and follow Military Road (Military Rd is on the west side of US-27) north until you get to Fletcher Road. Left (west) on Fletcher until you reach Naples Road (approx. 12 miles).

If you're coming in from I-75 get off at exit 244. Follow North Higgins Lake Road west until you cross over US-27 and follow the above instructions.

Once on Naples Road (some road signs call it Maples?) follow it south (approx. 5 miles) and you will see the Northmen signs and campground on your left.

A zoomed in map is below, showing Fletcher Road and Naples Road to the Northmen Site.