Thats a heck of a mulie
Mulies can be had in Okla. Some really good ones around Beaver, and the panhandle. There has been documentation of the mulie's and whitetails cross breeding in that area.
Now I'll have to post another picture, but in 1988 I was hunting south of the Kansas line in Kay county between Braman, and Blackwell on a creekline. When I walked out one afternoon, I spotted a rack sticking up from the grass in a waterway. When it didn't move, I thought it was dead or something, so I just walked up to it, and spooked a mulie up from its bed.

I shot him on the run at about 40 yds. Didn't have the money at the time to get him mounted, but I did save the rack. ;D A cow was killed the following year just a few miles from there. The grant county ranger has reliable reports of mulies in western, and northern grant county from last year. They are around. ;D