Read the headline and was immediately drawn in.
I'm in Wyoming also and I can tell you White tail bucks will breed with Mule deer does. Game & Fish Biologists indicate it is because of the much more aggressive behavior of the White tail buck. They will eagerly and effectively run off any Mulie suiters in the area.
The offspring are deffinately sterile and cannot reproduce. Not only that, but it is common knowledge that they are a little retarded as well.
It is because of the crossbreading that many hunt areas in Wyoming will read: "Mule deer buck, or any Whitetail". The G&F want to rid the area of Whitetails and any cross breads, in order to help the Mulie propogate properly.
It is a rarity however. Mostly because White tails prefer a completely different habitat than the mulies. Generally, White tails are the same here as elsewhere. They prefer low areas around creek bottoms where Mulies prefer Elk country like open prarie sage and/or high Alpine meadows even above timberline.
Nuff said?