Had a similar situation a few years ago in N Dakota--a former classmate of mine had a 15 year old bull that decided he wanted to be on his own..busted out of the fences..when my friend attempted to chase him back in the buff decided to get a bit aggressive on the F-250 Ford..severely damaged 2 sides...got a call from my friend if I wanted a chance to whack him with my bow..went back and found him feeding by some bales left in the fields..was able to get an arrow into him..he ran a bit and stopped..layed down punching the arrow all the way in..was finally able to sneak closer as he layed by some willows..got another arrow into him..he ran a bit and tipped over..

Have to say, ever since, my family and I have purchased bison meat every winter..very good and lower in fat...

Ripp