Bison or Cow Molar?

[tiars]

I was on a hike with my boyfriend yesterday along a lake in Central Alberta,  Canada when we came across this bone in the river. I know some of the discourse of using the stylid as an identification tool to differentiate between cows and bison but I can’t seem to figure this one out! Please let me know! 

[Rockwood]

I don't call myself an expert at this, but cow is my thought.