Google Maps also offers elevation information based on topographical maps. The United States Geologic Survey (USGS) offers a free topoBuilder tool that displays extensive information on detailed maps.

The U.S. Border Patrol's Big Bend Sector has deployed the Helen Gardner Aerostat, a surveillance balloon, near Sanderson, ...

The Aerostat is just one of many tools Border Patrol uses to maintain security across the U.S. southern border.