An alternate route to consider from Vermont and northern reaches is to cross I-84 to Scranton, and then come down I-81 to Harrisburg, and then I-83 (or other route) down the Susquehanna River. It's longer than the route through NJ, but far less subject to traffic jams.

If your road map doesn;t show Darlington, find Havre de Grace, MD (at the mouth of the Susquehanna where it empties into Chesapeake Bay). Now go upriver about 10 miles to the Conowingo Dam. Darlington and Camp Ramblewood are on the left shore, just a mile or so below the dam.

--Charlie