Fascinating story. I often hunt in New Mexico and the north Texas panhandle where the deer are heavy and the ranges can be very long, but I don't find deer hard to kill there either.
I bet you do run into huge deer that far "north".
I consider a 300 lb mulie to be a heavy buck.
Feel free to post a pic of any deer you ever killed....
I didnt know that Mule deer in Texas or New Mex got anywhere near that big.