Jim,
The differences between whitetail and mule deer from my experience are:
Whitetail are more spookier, mule deer are calm if bottle feed even more so.
Mule deer will not do well if kept in a wet dirt area, they like it dry. A good pen for them is on a hillside which drains well, no standing water. Mule deer will have to be wormed often at least every 40 days. They do well on good hay with pellets and some grain, not much corn in my opinion. They seem to get digestive problems from to much corn. I use wheat, peas and oats. They will love extra brush each day in their feed, leaves etc. I think back East they will need a method of fly control. If interested I have one to share.
I think most babies born back East will have to be bottle fed for them to survive well. This is just my opinion.