One other thought... Because it is a holiday weekend, many or most campgrounds in the area were probably full. People who would normally never camp at a National Park end up there because all the other CG's are full. We have camped at Julian Price many times and normally you only encounter people who love nature and would never trash up a National Park. But I do remember being there one year at a major holiday and encountering some really disrespectful people. Ended up discussing it with a Park Ranger and he said it happens around major holidays when all the other places are booked up.
Personally I still love Julian Price and want to go back again, but I don't think I'll ever go again over a holiday.