I read in a comment on 
brad's journal about Point Roberts, Washington—part of the United States, but to get to the remainder of the state of Washington by land, you have to go through Canada.
It's at the tip of a peninsula that dips just below the 49th parallel, the official latitude defining the Canada-US border in that area, so it's a fairly small area.
Apparently, school children often have had a hassle getting to and from school in past years, since everything after 2nd grade involves crossing the US/CA border twice, and border controls have become more onerous since 2001.
