4A, B, and C probably hold the bigger whitetails out west. Like you noted, they tend to concentrate down on the river bottoms and that spells doom for them during EHD outbreaks. 4E and 4D tend to have smaller WT bucks from my humble observations, but there are more of them because those units also include a fair amount of privately owned ag lands on the fringe of the rough stuff. Good luck trying to get permission to hunt that land, it's a tough way to make a living and the public stuff adjacent to it gets the holy hell pounded out of it by both WT and muley hunters. Enough so that you will see multiple sections of good land without a single deer on it by the end of the first week. Some stragglers start coming back on towards the end of rifle season, but that second week will make you think you are hunting the Great Deer Desert.
All that being said, I have taken a few decent WT's off of public land over the years in the Badlands units. Some of it was pure luck, some of it was a willingness to go home empty handed while spending an exorbitant amount of time hunting. WT's can be a really frustrating hunt out there. One thing is for sure, if you run across a WT buck and only have 2-4 days to hunt, you best seriously consider if going home empty handed is an OK option. You can go days at a time without seeing a WT on land you can hunt.
