They're checking permits more now that it's getting nice out. You can buy a permit from RAC to ride their land.
A local police officer did stop by the lot where we were parked, talked to a few guys for a minute, then left. I know for a fact the guys they spoke with did not have any permits, and they continued to ride. Make of that what you will. It's my understanding that a local group bought a lot of the trials around, and is opening a pay ATV park this summer as well, so you will be able to legally ride the area as long as you buy the required permits.