Antelope, are you serious? My Brother lives over by Pinedale, He's had lots hit out front of his place and I've almost grilled several my own self. I think the reason you don't see as many as roadkill is they are easier to drag off not being as bag as some of the other stuff.
The ones I've never seen are moose cause I imagine they end up walking or staggering away and there aren't a lot of them around, those and of course buffalo. I have some video of a buff traffic jam in Yellowstone I should dig out. Those things don't care about cars. They will walk right in front of you.
Never seen a lot of Elk on the road either.