That's a jack rabbit. They're huge compared the the cotton tails we chase around here! They'd probably chase the beagles!
Grandpa killed that mule deer close to the end of the hunt that week. He did some pump work for the rancher while they were out there, and as a way of saying thanks, he gave my Grandpa some pointers on where to set up on the property for a big deer. He saw a few good ones early in the week, but held out and was fortunate to get a crack at this one. I'm lucky enough to have that rack hanging up in the man cave.