Any idea what the airline will charge?

I spoke to a rep and Canada's airline regs are more liberal (I know - shocker!) than ours. Canada allows 70lbs and US 50lbs/bag and then there's some convoluted package size allowance.

I leave shortly for NWT and plan to bring my trophy back. Curious what others were charged when they brought their's back.

Did you check their contract of carriage? It should spell out the extra bag charges. Mine were recently $150 r/t for my rifle case. I had one duffel and the gun case only. They charged me $75.00 per leg of the flight for the gun case as an oversized bag. In the past I have packed light enough to bring my cape and horns (sheep)back from the Yukon in my main bag without any overage fees. The rifle case was something they (Air Canada) implemented within the past year I believe.

Check out Westjet. Only Air Canada charges the $75 bs for guns. FWIW Westjet is a better deal and has many flights out of US

I'm flying Northwest Airlines to Minn and then connecting with Canadian North to Norman Wells. The folks at Uniglobe indicated there would probably be some fee as the bag the horns and hide would be in would probably exceed their size (not weight) requirement.
The Stone sheep I got last year I had shipped back. For the Dall sheep, I'd like to bring it with me.
No way to get everything in one bag as I'm bringing my rifle also.

I know Northwest charges beyond bag #1. Enjoy your hunt.