Guy, I had a post from the old board concerning the pits. I copied it below:
When you were young and full of yourself, did you ever happen to party at the clay pits north of route 72 near Woodmansie (circa 1970-1980)?
What a hoot that was, and what a strange section of the pines it remains to this day. Old maps list this area as the Union Clay Works. It is south by southwest of Pasdena, so that makes sense.
The 2 main pits have been dug down to the water table and are constantly full of water with a green tint due to the light bouncing off the clay (my supposition). You can still see cars at the bottom in several locations from some of the more wild and crazy guys.
There is (or does not appear to be) no water outlet in the area. This is generally a very high area of the pines with the average elevation around 180 feet with several nosebleeds up to 200 or so feet.
Just southwest about a mile is the abandoned town of Red Oak Grove. At least I think its a town. In Jack Cervetto's book he says there was a large building there wherein they made clay pipes etc.
This entire area was a party town for many years, from the smoke hazed hippie days all the way through the disco years. More than one person was killed or seriously hurt climbing the clay embedded walls on motorcycle or quad. It was quite a feat--you would get about 3/4 of the way up, and the clay would start to cause your wheels to spin, and then all hell would break loose.
I camped there one time around 1971, and there was a roving patrol of sherrif deputies busting people for smoking a little pot. Real crazy times.
The main road in started at the railroad tracks at Woodmansie. The road was taken over by a sand company, and they have dug the biggest damn hole in the pines I have ever seen. It is huge. You can look down and see a barge with a crane on it sucking sand and gravel out of the bottom of the lake and transporting it via elevated pipe to the main distribution plant. They have already sucked one hole clean, and have moved on to another. They planted trees in rows all around the abandonded hole. It looks kinda funny, like it doesn't blend in with the pines. But don't get me started on sand and gravel plants, thats another story altogether.
This is an important area ecologically. As the ground slopes away in all directions, several main creeks are have a portion of their source where the ground begins to level off; the Cedar Creek, the Rancoacas Creek, the Wading River, and its sister, the Oswego.