Search:

OK, it wasn't on McCauley mountain, it was called McCauley quarry and yes it is off of Dairyland road on privately held properly.
And the "old map" that Roy Underhill shows in the magazine article...

I'm 90% certain it was on McCauley mountain, but it was 10 years ago. There are small quarries all over the mountains, some dating back to before European settlement, so Pickard Mill area may be yet...

I'll dig around this weekend and see if I can find the map.
The article by Roy Underhill has some hints to the location in it, but it also has some misleading information in it - probably done on...

If I remember correctly, the mine is about half way up the western side of McCauley mountain. There is a gravel road that will get you within about a 30 minute walk to mine and there is a good path...