The Sept. 11 terrorist attacks have raised concern over security issues along the U.S.-Canada border. Minnesota and North Dakota have 30 ports of entry into Canada. Protecting all of them is no easy task.

	Millions of people cross the border between the U.S. and Canada every year, and account for billions of dollars in economic activity. (MPR Photo/Dan Gunderson)

Keeping the border secure

The Sept. 11 terrorist attacks raised U.S. border security to its highest level. That means extra work for the people who monitor dozens of border crossings. It can also mean lost time and money for those who cross the border. Read | Listen

Who's guarding the border?

Congress is moving forward with plans to upgrade the resources used to guard the 4,000-mile stretch of border between the U.S. and Canada. But until those promises become reality, who is protecting our northern border? Read | Listen

A safe port

Duluth-Superior is the busiest port on the U.S. side of the Great Lakes. Port officials say they are thinking a lot more about security, and taking various measures to protect the port. But since it's 1,000 miles from the nearest ocean, they say a terrorist attack here is unlikely. Read | Listen

The view from Canada

The communities of International Falls, Minn., and Fort Frances, Ontario, have a casual, sister-city relationship. But things changed after Sept. 11. The friendships are still there, but tightened border security has slowed commerce and made some people reluctant to cross the border. Read | Listen

How the border got there

To most Americans, the Canadian border is something that has always just been there. But historians will tell you the search for the border was far from easy. It took 60 years of exploration, negotiation and compromise to decide where the border ran. Read