Hey Pawn Stars stars, next time you go camping, clean up your mess!

That's what cops in Glamis, California were telling Rick and Corey Harrison -- aka the pawn shop owner and his son -- after they left trash at a campsite over the Thanksgiving weekend.

Police discovered a ton of trash where the Harrisons, along with some friends, were camping. The slew of beer cans, garbage and barbecue grill were apparently enough to fill up 10 bags.

Dumping trash in the campgrounds is very much illegal and not taken lightly. So much so, the word is that the guys were fined $1,000 each!

However, Corey Harrison told TMZ, "We left the campground before our buddies did and they were to clean it up and apparently didn't follow through.  My father nor I were cited."