I am not female and I hike solo 99% of the time. I have run into a few folks who have been drunk or looking for a same sex partner over the years. I have even run into a couple of females looking for more than a hiking partner. This situation has always been very near to a parking spot. Once you get 1+ mile from a parking lot you are not too likely to run into the undesirable types. My best advise would be to camp away from any area with easy access.If someone strikes you as odd, move on. Predators are generally too lazy to go far from their car.