I think it is meant to be a lot deeper than you might assume. So you wouldn't see bodies piled up 10 feet down.
There are hundreds of ways to have someone come across it. That's easy. FBI looking into their deaths could easily find traces of them before they went missing. And just because they got paid cash at the Yellowstone, doesn't mean they didn't use credit cards in the area, had cell calls in town, or had eyewitnesses that they were in town. Maybe even with the Yellowstone crew at events or even at the ranch. Then think of all the decades of people that have families of friends who might want to make things even since the law won't be able to. They would be looking over their shoulder constantly, wouldn't have a convenient place to dump bodies, and so on. Could put a lot more pressure on the Yellowstone. Let's not forget Governor Dutton as well.
I just see it opening up a lot of new people wanting to end the Yellowstone and the Duttons. I just see it as a great way to limit their moves, corner them, and have them on the defense a lot more. The overly bad ass, we'll just kill and dump them is played out.