 In May 1960, the CIA began to recruit anti-Castro Cuban exiles in the Miami area.For most recruits, infantry training was carried out at a CIA-run base code-named "JMTrax" near Retalhuleu in the Sierra Madre on the Pacific coast of Guatemala.In November 1960, with Gregorio Aguilar Matteo spearheading training with 430 men, the leaders were chosen and the group was named Brigade 2506.