No, mule deer do not have any mule genes in them. They're pure deer. The name comes from their appearance: their large ears look like mule's ears, hence the name. Mature males, known as bucks, usually have symmetrical antlers with several forks and four or more points (tines). Their habitat varies from grasslands to forests, and in Western Montana, mule deer are generally more migratory than whitetail deer. Mule deer are found throughout Montana, and have adapted well to sharing their habitat with people. In fact, it's not uncommon for muleys (as they're affectionately known) to "share" some peoples' backyard gardens.
Generally, Mule deer are loners, only forming herds during the breeding season in late fall. Does have one or two fawns in the spring that are grayish-brown with white spots. If you're a spring hiker, you may stumble upon a fawn sleeping in a sheltered place. It might seem as though the fawn is abandoned, but the mother is always nearby. The fawn is just doing what it instinctively knows to do in the face of danger: hide. If you find a fawn, do not disturb it or try to feed it; the mother is watching nearby, waiting for you to move on.