The best way to get a camping pass is to get one at the packet pick up the day before your race.  They will have the camping passes. They're $10 for one or two nights. Please bring exact cash.  If you can't make it to your packet pick-up, please make other arrangements (reach out to the RD via email well in advance). 
If you're running the 55K, please come find the RD at the start/finish line in the park on Friday.  He'll have the camping passes there.
The park where camping is available for the race is at Trailhead Park (right at the start / finish).  It is a city park and they only allow camping on the night(s) of the race (Thursday night and Friday night - there is no camping on Saturday night).
Camping is allowed in tents, RV's, campers, etc.  There are no hook-ups.
Thursday night (the night before the 50 & 100-milers start) is pretty quiet in the park - although we do start setting up in the park at 5:00 AM or so on Friday.  The early starters start at 6:00.
Fair warning!  On Friday night there's a lot of light, noise & activity in the park as it's also the finish area for the 50 & 100-milers.  There are darker corners to go camp in, but I can't guarantee a good nights sleep.  Bring ear buds!
The good news is, there is a restroom with flush toilets there!  But, no showers.  I mean, c'mon... it's $10.
The park only allows camping on the night(s) of the races and at no other time.
Thank you!