Poor etiquette is almost (but not) expected as some locations that get hammered, even with all of Montana's water, but this is a bit much. We happened to be fishing near the president of the Henry's Lake Foundation who fishes this stretch often (the Madison River in between Hebgen and Quake lakes), and he said he's never seen manners quite this bad. Myself and Ben, the prez, and the boat were the only folks around, but they needed to fish there.
We had fished that stretch for a couple hours and were about on our way out anyhow, but the boaters didn't know that. Maybe we should have started a knife fight (as apparently happens at some Eastern fisheries that get unbelievably pounded), and maybe we should have at least spoken up, but if they don't already understand common everyday manners about personal space, I don't know that we'd have helped.
Henry's Lake guy was sure it was a guided trip, but I cannot be sure as we didn't see any tags. We do know they were from Idaho.
Ultimately, I am glad I am able to fish in a place where breaches of etiquette rarely exist, but that doesn't excuse them when they do.
These hillbillies will get their comeuppance in due time if they keep it up.