The last time I was out that way (more years ago than I can remember) it was all posted as private property, no trespassing even though it was listed as a California Historic Landmark and there were signs off 101 that directed you right to the entrance (several miles up in the hills). I never figured out how a private resort merited such signage (all paid by the state, of course).

The property was apparently sold to the state in 2003 and added to Henry W. Cow State Park. However, the area remains closed until they implement a management plan, which could take a very long time knowing all the red tape involved. You can read about it on Wikipedia: en.wikipedia.org/wiki/Gilr...ot_Springs

It is amazing. Unfortunately the rangers are on to it and are giving tickets at the tub itself now, no longer just waiting at your car. Good luck!