U.S. Customs and Border Protection Report to Congress on Ongoing DHS Initiatives to Improve Security Along the U.S. Northern Border [open pdf - 376KB]
"The international boundary with Canada extends 3,987 miles across both land and water, and it is often described as the largest open border in the world. It separates two friendly nations with a long history of social, cultural, and economic ties that have contributed to a high volume of crossborder trade and travel. Almost all of Canada's major metropolitan areas are located on or near the international boundary. In fact, 90 percent of Canada's population lives within 100 miles of the border. While legal trade is predominant, there are networks of illicit criminal activity and smuggling of drugs, currency, people, and weapons between the two countries. The long, porous nature of the U.S. Northern Border provides a multitude of opportunities for clandestine and undocumented crossings. The primary threat along the Northern Border is the potential for extremists and their conveyances to enter the United States undetected. The challenge of securing U.S. land, air, and sea borders is vast and complex, and involves the ongoing work of multiple Department of Homeland Security (DHS) components, as well as other Federal, State, local, tribal, and international efforts. While this report focuses primarily on the efforts and initiatives of the U.S. Customs and Border Protection (CBP), which serves as our homeland's frontline border agency, the enforcement efforts of United States Coast Guard (USCG) and U.S. Immigration and Customs Enforcement (ICE) also play a vital role in DHS's efforts to protect the United States against threats to our border."
United States Department of Homeland Security: http://www.dhs.gov/