During the first years of their existence, the Commands were faced with incursions by Maquis who infiltrated with subversive propaganda and material for use in acts of sabotage inside Spanish territory.
Beginning in 1945, the members of the 223rd Border Command of Jaca, who patrolled the Aragonese Pyrenees, attended ski instruction organized by the 51st and 52nd divisions of the army.
In 1954 the training program was removed from army oversight, and ski courses began at the Civil Guard barracks at Coll de Ladrones in the Aragon Valley, attended by members of the Border Commands of Pamplona, Tremp, and Figueras, which, together with the Jaca command, provided full coverage for the Pyrenees border.
The emerging Spanish middle class were starting to enjoy the natural beauty of the mountains, and began suffering accidents.
The initial deployment in September 1967 had little success, since the guards were intended to remain in their bases and come to the rescue only when accidents occurred, without a period of training and maintenance of their level of expertise.
In 1992 the International Commission for Alpine Rescue acclaimed the Mountain Service as one of the four best in the world, together with those of France, Switzerland and Austria.
The tasks assigned to the Civil Guard Mountain Service are as follows: Although these Civil Guard units have been generally known as GREIM, in fact the units are currently of several types: SEREIM (Sección de Montaña), made up of about 15 specialists under the command of a Civil Guard officer; GREIM (Grupo de Montaña), made up of about 11 specialists under the command of a non-commissioned officer; and EREIM (Equipo de Montaña), made up of 5 or 6 specialists under the command of a corporal.
The centre has provided training for mountain service staff from other countries, and works together with the French Gendarmerie and the Italian Carabinieri.