As long as you are parked I area with others your stuff will be ok...but yes keep it locked. On the trail....do not leave stuff alone and unattended..it will be striped and burnt...especially as its getting close to or is dark.
Someone who knows there way around is a must....i have been 4 times and spent multiple days on the trail each time and I still get lost easily.
The place is a absolute blast to wheel!
09 Dodge 2500 w/ a Cummins, dd/towrig
85 Toyota Pickup, 1tons, coilovers, 40's, ect