At the end of the 1990s the group had much control over the rural areas connecting the urban centers of the Caribbean region, but in the 2000s was forced to retreat into the more inhospitable Andes.
The group's leaders have been held responsible for numerous kidnappings and killings along the entire Caribbean coast, including the urban centers Cartagena, Barranquilla, Valledupar and Santa Marta.
This bloc was also the center of the high-profile kidnapping of Fernando Araújo, who recovered his freedom during a Colombian National Army offensive in early 2007.
The 37th Front had a historically strong presence in northern Colombia, once controlling large amounts of territory.
This urban network was directly composed by 30 combatants, although it was suspected to include a much larger number of members.