Steve,
Larry Brown and I have been telling people since about 2000 that we were in the last of the great haydays for wild pheasant hunting and if we all didn't get into as much as our time and resources would allow, we would see it disappear without enjoying it.
I am afraid that those days are here. The high price for corn because of Ethanol, CRP disappearing with the termination of the farm bill that supported so much CRP, the Bakken Oil Boom and three killer winters in a row starting in October of 2008 has pretty much sounded the death toll for wild pheasants on the High Plains.
What happened to the superb pheasant hunting around Sterling and Holyoke CO in the mid to late 70's is now wide spread from Kansas to the Canadian line.
If it was me and all I wanted was a place to run the dog without being over run by other hunters, I would hunt the Highline in MT somewhere west of Shelby, perhaps. You would have to put in some miles per rooster, but you could shoot some birds and the MT birds of opportunity, the Hun and the Sharpie are always a maybe for the bag too. You might want to do it this fall, though. The oil play is sprawling it's way to Cut Bank.
You mention west river and for years I hunted a 12,000 acre farm that straddle both sides of the ND/SD line. The landowner invited friends in for the SD opener and 20 or more hunters would harvest 60 birds on each side of the line and we would not even dent the bird numbers.
That land has been sold and is now farmed from bar pit to bar pit and I know that three hunters are now hard pressed with good dogs to get a limit in either state. I still have access to adjacent lands over there and that is just what it was this past season.
