I hope this helps in regards to your clothing optional question. A few years back I was hiking in to the springs from Bowen Ranch on a rather warm day. About half way down I ran into a couple of rangers hiking out. One of them appeared to be suffering from the heat and I offered her one of my water bottles. She thanked me and as we were stopped we engaged in a bit of conversation about the weather and such for a few minutes while she rested and drank some water. I was curious myself about the extent of the clothing optional area and inquired as to the limits for nude activity there. She smiled and said with a sweep of her hand "You can be nude anywhere here.". That was good news for me as I was hiking nude at the time. So there is that and the FS rule about no nudity within 1/2 mile of the T-6 crossing at the start of Bradford Ridge Trail and it sounds like most of the area is C/O including Bowen Ranch. Hope this helps and I stand corrected in advance if anyone with more knowledge on the subject has other information disputing the above.
Jay