Although this may not apply specifically to the migrating wildlife from North Park, I can give an idea of the winter conditions in the Upper Platte valley.
Unfortunately, this winter has been extremely tough on wildlife in south-central Wyoming. A friend of mine that lives out at Cow Creek (right across the highway from Baggot Rocks) has been able to walk up the drift in front of his house and step on to the roof. This guy is a wildlife biologist and pays attention to the local critters, and has commented that he's seen poor body condition and starving animals (first antelope, and then deer) since January. We're just now starting to get an idea of the winter-kill as we're finally losing some snow and the carcasses are becoming visible in the bare spots. I've heard numbers thrown around of between 40 and 50% winterkill all through Carbon County. The winter ranges on the west side of the divide probably fared worse than on the east, but it will remain to be seen. Many long-time Encampment residents are saying that they haven't seen a winter like this in 25+ years, or in some cases ever.
Last I had read, WGFD is planning on manipulating harvest levels because of winter mortality from Muddy Gap south through the Rawlins areas, and especially in the Baggs and Platte valleys. I imagine we're looking at reduced limited quota tag allocation and severely shortened season lengths in the general areas. We'll find out at the April season-setting public meetings. Based on what the conditions have been like on winter habitats this year, you may be looking at some significant winter-kill on older and younger, weaker animals. We'll see the affect on older bucks this next year, and then have to deal with several future years missing age classes as the yearlings have taken it in the shorts this year, and starving does will have re-absorbed their fetuses.
Sorry for the grim news...