Antelope bunch up into huge groups for most of the winter, then this time of year they start to spread out back onto the other areas in their ranges. This can make winter counting challenging...
Bear in mind that there are very few true migration antelope hunts. Many of them tend to be what is there at the moment is what you are hunting. The exception tends to be any unit that runs two separate hunts, especially if there is a later start date for one of the tags. The other exception is long season dates for units that butt up to the major mountain ranges. After the first major storm you will see new bucks in the lower country as the goats will leave the higher elevations are are antelope friendly.
FYI, there is an elk unit I have hunted here, 6 miles back in the wilderness...that had respectable bucks in country almost 11,000 feet in elevation.