Of the 15 roads that cross from Montana into Canada, only three are open around the clock. Highways 93 and 15 and Road 16 (in the state’s far northeastern corner) have 24-hour ports of entry. U.S. and Canadian citizens should carry their passports to cross the border—even if you can get across the border in one direction with a driver’s license and a birth certificate, there’s no guarantee that you’ll get back across in the other direction. Everyone has stories of stranded travelers caught on the wrong side of the line.
Citizens of any other nation should be prepared to show a passport and the appropriate visas. Citizens of any country may be asked to provide proof that they have sufficient funds for their intended length of stay.
Customs allows each person over the age of 21 to bring 34 ounces of liquor and 200 cigarettes into the United States without paying duty. U.S. citizens are allowed to import, duty-free, $400 worth of gifts from abroad, and non–U.S. citizens are allowed to bring in $100 worth. Should you be carrying more than $10,000—in U.S. or foreign cash, traveler’s checks, money orders, or the like—you need to declare the excess amount. There is no legal restriction on the amount that may be imported, but undeclared sums in excess of $10,000 may be subject to confiscation.
Adults (age varies by province but is generally 19 years) can take 40 ounces of liquor or a case of 24 beers as well as 200 cigarettes, 50 cigars, and 14 ounces of tobacco into Canada. You can bring in gifts totaling up to C$60 in value. Pistols or handguns cannot be taken into Canada, although hunting rifles can be.