I've been curious if once the elk were mixed in with the deer herd were than any negative effects?

I have heard from many when talking about releasing a herd into west central Illinois that it would have to many negative effects on our trophy hunting. No proof or homework done by me, I'm ignorant to this topic.

Others have said that our terrain here was not suitable for it and the competition over cover and food would not be suffecient enough to support a healthy population. I think I have heard before there is a small population in So. Illinois though...