Keep them defined to the easement along the crickbed and off of your fields -
Contact an attorney and get the warning letters out ~
Heck, I can threaten legal action for what you posted on AgTalk - it doesn't mean anything .  . . .
Keep them off your property and on the established easement, untill it goes to court.
As far as the tittle insureance - It won't help, it'll say theres a defined easement along the crick bed . . . 
Good luck