Correction, sorry
Yes you can take Rt 78, but then when you can merge onto 22 in PA (the last time you can merge) take 22 east over into NJ, then as soon as your in NJ, merge onto Rt 57, take Rt 57, until 519 (a mile or 2), make a left onto 519 North, then about another mile make a RIGHT turn onto Fox-Farm Road, the sign will also say Merrill Creek, go up steep hill, and follow Fox Farm around lake until you see a bigger sign for Merrill Creek, follow to boat launch.
And Mike, the hills in this area are nasty, TomMac's (from this site) buddy's trailer almost caught on fire coming down one of the hills last year, brakes tend to get pretty warm!!