I have had an ongoing discussion with friends about this subject. Some say never, some say it happens all of the time. I have done some research on the web but only find weak sources at best. What do you think? Do whitetail and mule deer cross in the wild? And if so, what is the proof other than my friends brother-in-laws cousinshot one in '62 that F and G said was cross. Point me to some hard facts so I can settle this argument. Thx.