Carl Norton, the lead training officer, observes U.S. Border Patrol agents who are attempting to qualify for the agency's horse patrol units in the Tucson Sector. Friday was the last day of training for the three-week course. (Mark Levy-Herald/Review) HEREFORD -- What is past is not necessarily just history. In today's world, the U.S. Border Patrol is employing an old method to help monitor the U.S.-Mexico border to help stop the flow of illegal immigrants and drugs. The agency is re-establishing horse patrols to reach many of the trails used by people and drug smugglers in remote areas of Arizona...