When did the CNJ retire its F3s?

[Overmod]

Flintlock76

Yes, the Lehigh & Hudson River ran through Vernon/Great Gorge.  The trackage is still there and used by the Susquehanna now.

Perhaps an interesting note, from a Wikipedia article that does not cite the source:

During the mid-1970s, the L&HR became part of a proposal to run "Bunny Ski Trains" between Hoboken, New Jersey, and the Playboy Resort (Great Gorge) in Vernon, New Jersey. The proposed service, which would have run on weekends during the winter, would have retrieved passengers westbound along the Erie Lackawanna Railway's (EL) Morristown Line to Netcong, New Jersey, then run along a short section of the remaining Sussex Branch to Andover Junction in Andover, New Jersey, and then northbound along the L&HR to the Playboy Club. The service would have utilized EL's new commuter consists, but was met with stiff opposition from EL management, which was anticipating a merger with other northeastern US railroads and did not want to enter into a venture that it viewed as a potential money-loser. The Bunny Ski Train remained a viable proposal until the remaining vestige of the Sussex Branch was removed in July 1977, after it became clear that it was no longer needed as a connector to the L&HR.

[Flintlock76]

Yes, it'd be interesting to know what the source was, this is the first I've heard of that proposal.  The L&HR would have had to use EL passenger equipment, they had none of their own.  

[Overmod]

Flintlock76

The L&HR would have had to use EL passenger equipment...

Would have been the lightweight equipment (now I think called "Comet I") and the U34CHs, a sensible use of the equipment over the weekend when it would otherwise not be used.  An issue was that these could not handle ski gear very happily.  

ISTR this proposal came up and was discussed at some point during the planning to build the short rail spur to the Meadowlands to make it more convenient to watch the North Arlington Giants play.

I dimly recall that adding some special 'hospitality' bar car service was initially part of the idea, as such a section might have lucrative patronage in regular service; the idea had been popular 'across the river' (technically more than one of them) and this was, in fact, later extended to modern equipment there, and there was at least one train club that had paid for its own 'accommodations' on the ex-Lackawanna and some version of that concept inside a couple of the new cars might be extended on a couple of the NJT services.  Probably wouldn't have gone anywhere, and would have involved more planning to get the 'right' train on the right service, but might have affected the perceived 'money-losing' aspect of the trains at a time EL probably could have used the revenue and publicity.