Winter weather, vast expanse make patrolling Canada-U.S. border a daunting challenge

Last week's Canada-U.S. border tragedy captured the imaginations of Canadians and U.S. citizens alike and underscored the challenge border guards confront every day as they patrol the vast, unforgiving hinterland.

The U.S. Border Patrol agent is standing alongside a similar facility in Minnesota that she says undocumented migrants use as a meeting spot when sneaking over from Canada, usually under cover of darkness.

At the moment, it's a blindingly bright, sunny day, beautiful in every respect but the -29 C temperature.

"Oh, this is very mild," says Siemer, the deputy patrol agent in charge of the station in nearby Pembina, N.D., nary a trace of sarcasm in her voice.

"It's about -20 degrees (Fahrenheit) right now, but the wind isn't blowing, so it doesn't feel that bad."