A 300 pound mule deer is still a big one.
But taken across their range I think the mule deer seem to run a bit larger on average based on what I have seen myself. I have seen a few in Wyoming and in northern Alberta that were stupendous. Kind of a visual shock for a moment after looking at more normal-sized deer.
No doubt that mulies run bigger than whitetails. I worked for an outfitter out there for a couple seasons and we saw some real monsters. On the Air Force Academy I once saw a few bucks running together and I'm pretty sure a couple of them would have gone 300 or more... Couldn't hunt them then and there but my trigger finger went to twitchin'....
In my opinion a muley is a lot easier to actually get. We used to take a day off every once in awhile and borrow the horses and spotting one and riding around behind him and doing a bit of climbing and crawling and we usually got our buck. It wasn't rocket science but it WAS hard work.
I rode a mountain bred appaloosa and he had absolutely NO fear of blood or bloody carcasses and we could load a mulie on him and me too and he just grunted going uphill but he always brought home the bacon. I miss that horse. He picked me out the first day I went to that ranch and I never rode any horse but him. I trusted my life to him almost daily and never had a doubt he'd get me through. I think he was half mountain goat.... LOL
Sorry guys.... I'm rambling....
$bob$
