Wyoming Game and Fish field personnel collect a variety of data throughout the year to determine big game population trends. One of the more telling pieces of data to provide a picture of the future trend in mule deer is the fawn winter survival data, or the change in ratio survey. It meaures the number of fawns (per 100 does) both at the beginning of winter and at the end of winter. This year's results show just how variable the winter impacts were in western Wyoming. 
For the northern portion of the Wyoming Range, winter ranges around Big Piney and LaBarge (Deer Hunt Area 143) there was only an estimated 13% fawn loss, which is about average. For the southern portion of the herd, winter ranges closer to Kemmerer (Deer Hunt Area 135) there was a recorded fawn loss of approximately 50% and even higher at almost 70% further south near Evanston.