Need help with unit 99 turkey tag please

My wife drew a tag for unit 99 that is Mercer and Oliver County. This is her first spring turkey hunt, I want to make this a good hunt for her. I spent the last week scouting public land, walking through water snow heavily wooded areas with no luck. I have knocked on farms doors offering to pay them or work for them, I keep getting the same answer "there no turkeys here." I just need a good starting point. Any help would be appreciated, you can pm or call if you would like 701-390-3708. 
                                                   Thank you.