well I suggest doing a search here on this site a while back there was some folks here that were looking to hunt them and even had places to go
next I would try calling the wildlife officer in area's you think have issue's
as if farmer are getting damages, I am sure they would know, as I'd bet they get a ton of complaints from farmers
and that could lead to tips on where to hunt, or even priavte land owners who might let you in on there lands for hogs, as they can be a terrible critter to have about doing a lot of damage in a short time and they breed so fast
I wish I lived closer to where there were hogs, love to go kill some, for both good eats, and to help out on controling them
good luck