The Montreal agencies generally post in Canadian dollars.  The exchange rate today is about 16% ($1usd=$.84cdn) which would mean $180cnd is about $150usd... geez, does anyone else remember the days of 25%+ rates?

I would suggest either exhanging your US money at a US bank before you leave, or wait until you are there and use an ATM.  You'll get a better rate, or a smaller service fee that way.