xtinkshun, Deep Creek is safe is you remain vigilant and aware of your surroundings at all times. There have been several historical problems which some people consider major items. Car vandalism is a potential problem if you don't pay your 5 bucks to Mike Castro to park on Bowen Ranch property. Intermittent petty thefts also occur at the springs. My friends and I have had cameras, food and water stolen from the springs. When you're at the springs, be aware of the type of people there. Use your judgment -it's pretty obvious when people drink too much or use drugs and their behavior towards others changes drastically. I have seen situations like this escalate into verbal confrontations, fistfights, a knife fight, and even a few gun waving activities. I'm not pickin' on Deep Creek, this kind of stuff can happen anywhere.
Regarding Mike Castro, opinions about him run the gamut. Many see him as a decent individual doing his best to represent BLM and the Forest Service as a gatekeeper. Others see him as a violent, irrational, motorcycle chasing, short tempered fusebox who will kill you if you look at him the wrong way.
Read some of the information about him at this website. Keep in mind this is one person's subjective opinion.
With all this said, don't be spooked. Many of us have safely enjoyed the place for many years. So give it a try, it really is a magical place....