There are potentially numerous border crossings on your way to Alaska:
1. Cassiar Hwy - between Hyder AK and Stewart BC (there is no customs house crossing from Stewart to Hyder, just one on your return to Stewart from Hyder but they seem to not be too busy so often ask lots of questions - wanted to know if we had any knives!?)
2. South Klondike Hwy - between Whitehorse & Carcross YT and Skagway AK
3. Haines Hwy - between Haines Junction YT and Haines AK
4. Alaska Hwy - between Beaver Creek YT and Tok AK
5. Taylor/Top of the World Hwy - between Tok AK and Dawson City YT
So get used to answering the questions and feeling comfy crossing the borders.