The Jungle Operations Course included in-field exercises. For example, in 1966a company of 103 students from Panama and 4 other Latin American countries enrolled in the Jungle Operations Course, U.S. Army School of the Americas, Fort Gulick, Canal Zone, recently completed a 9 day tactical exercise crossing the Isthmus of Panama, a ground distance of about 55 miles, through jungle, swamp and water. Symbolically following in the footsteps of Spanish explorers 300 years ago, the crossing began with an amphibious landing on the Pacific side of the Isthmus. The exercise ended with the last student completing the trek by emptying a container of Pacific Ocean Water into the Caribbean. The 9 day exercise emphasized jungle operations and tactics and techniques of combat in this environment. The U.S. Army School of the Americas' Jungle Operations Committee supervised and controlled the maneuver.Heightened tensions in Southeast Asia increased demand for "jungle operations techniques". In 1966, the army ordered the Commander, U.S. Army Forces Southern Command, to augment the school's Jungle Operations Course to accommodate more students. Specifically, these new students were to be soldiers "enroute to assignments in units serving in the Republic of Vietnam." A feedback-loop created between the school and General Westmoreland's headquarters allowed the Army to ensure that "lessons learned" in Vietnam were incorporated into the curriculum. Scholar J. Patrice McSherry has argued that methods derived from Vietnam and incorporated into the curriculum included "torture techniques and other dirty war methods". Further, the school leveraged instructors returning from service in Vietnam to "insure currency of the instruction". As new techniques were developed and adopted, the military became increasingly protective of course content. According to one scholar, by the mid-to-late 1960s "trainees required security clearances even to view the course descriptions of military intelligence courses."