I owe restitution from '05 for a destruction of property under $1000. If they got rid of the property that was "destroyed" (a fence) do I Still owe?

What the owners decided to do with the fence has nothing to do with what you owe.  If you cause $500 damage to my car, you would owe me $500, whether I used the money to repair the car or left it in the same condition, or junked it.  However, you do not state either that you were sued for the damage, or that you agreed to pay for it.  While I am not familiar with Wyoming law, after 9 years, I'd be very surprised if the statute of limitations on the property owners' claim against you had not expired.