I don't remember a roller coaster that large being there, but I was probably around 12 years old the last time I was at the park and am now in my 40s. There is now a flea market there every Sunday. I have been told that no one is allowed in the part of the park where the old derelict rides are located. I may try asking the park owner personally sometime about the possibility of detecting there, perhaps as a group activity.
I have emailed the race track there and they proceeded to reply back that the track owns the park and it's now private property and they WILL NOT allow anyone in there to detect, or do anything for that matter. I live about 4 minutes from this place. Long before it was an amusement park it was picnicking area in the late 1800's (or so I've read). I think it would be a killer spot, just got to find the right person to talk to. I haven't given up hope yet. There is a creek the runs right along the property, I've thought about detect it. I talked with a law enforcement officer a awhile back and he said there should not be any legal issues with detecting the creek as its owned by the people of the commonwealth of Pennsylvania. He said as long as I am not on private property then there is no problem. I'm just not sure if someone saw me in the creek swinging if they would run me out. I really don't know the laws pertaining to creek hunting and the last thing I want is to have a police officer show up and fine me or take my equipment.
I am new to creek detecting. Could you define navigable. It flows through many cities and townships and the general public can access this creek in many areas for fishing and tubing. Does that consider it navigable?