hi there.. actually we're on the same boat.. I had my work permit before, then extended my stay as a visitor and back to work permit again... what you can do is , send your application for work permit outside canada (Los Angeles or New York ) . you can see the how's and what's at cic website.. ( application of WP outside canada).. you can see how long the processing time is.. after submitting the application , in a month or two you'll be receiving an approval letter allowing you to work in Canada.. that is just a piece of paper.. that is what you'll bring together with passport at the border nearest @ your place, that's Montana..no need to have a us visa coz you're just doing a flagpole exit..the US immigration officer will just directing you to their building to sign some documents that stating you're just doing a flagpole exit... then you'll back to canada border office and apply for work permit ..