<P> The Mexico -- United States barrier is a series of walls and fences along the Mexico -- United States border aimed at preventing illegal crossings from Mexico into the United States . The barrier is not one contiguous structure , but a grouping of relatively short physical walls , secured in between with a `` virtual fence '' which includes a system of sensors and cameras monitored by the United States Border Patrol . As of January 2009 , U.S. Customs and Border Protection reported that it had more than 580 miles ( 930 km ) of barriers in place . The total length of the continental border is 1,989 miles ( 3,201 km ) . </P>
<P> The Mexico -- United States barrier is a series of walls and fences along the Mexico -- United States border aimed at preventing illegal crossings from Mexico into the United States . The barrier is not one contiguous structure , but a grouping of relatively short physical walls , secured in between with a `` virtual fence '' which includes a system of sensors and cameras monitored by the United States Border Patrol . As of January 2009 , U.S. Customs and Border Protection reported that it had more than 580 miles ( 930 km ) of barriers in place . The total length of the continental border is 1,989 miles ( 3,201 km ) . </P>
how much of the us southern border is fenced
how much of the us southern border is fenced
more than 580 miles ( 930 km )
more than 580 miles ( 930 km )