Infantry Drills

2-55: Operations in Mountainous Terrain

Previous: 2-53: Subterranean Environment

2-55. Combat in mountainous areas present units with complicated hazards, difficulties, opportunities, and risks. Mountainous combat operations call for high levels of physical fitness, mental toughness, endurance, and tactical and technical proficiency on the part of all individuals.

2-56. A disciplined and prepared Infantry platoon and squad is task-organized with and supported by other members of the combined arms team, which are crucial to small-unit mountain operations. Units fighting in mountainous areas, overcome difficulties, measures risks, and exploit opportunities to close with and defeat the enemy. Prepared leaders anticipate, understand, and adapt to physical demands of mountainous environments. They face and overcome challenges of fighting in areas where technological supremacy can be negated by crude and nontechnical enemy actions. Unit leaders who know what to expect during mountainous operations create situations allowing their units to adapt to challenges and achieve victory in all environments.

2-57. Infantry units conducting operations in mountainous terrain are able to adapt and skillfully use environmental challenges to their advantage. (Refer to ATTP 3-21.50 for more information.) The landscape and climatic conditions create a unique set of mountainous operations characterized by—

  • Close fights with dismounted Infantry. Mountainous combat often is close in nature as opposing forces meet on rugged terrain. Though engaging targets near limits of direct fire weapons occurs in mountainous engagements, intervening crests, hills, ridges, gullies, depressions, and other terrain features often limit long-range battles with the enemy. Upper levels of mountainous terrain are characterized by lack of trafficable roads. Use of vehicles often is restricted, forcing dismounted operations.
  • Decentralized small unit operations. Conflicts in mountainous environments are often fought on platoon and squad level, as terrain commonly does not support movement and maneuver of large units. Compartmentalization of mountainous terrain can separate brigades from battalions, battalions from companies, and companies from platoons for long periods. As altitude increases in mountainous environments, terrain generally becomes more rugged and restrictive, which drives the need for decentralized execution of missions by dismounted platoons and squads.
  • Degraded mobility and increased movement times. Ruggedness of mountainous terrain often restricts mobility to foot movements using file-type formations on roads and trails. A relatively short distance from point to point may be an arduous movement over steep, rocky, uneven terrain with multiple trail switchbacks increasing distance traveled and tremendous energy expenditure.
  • Unique sustainment solutions. Sustainment in mountainous environments is challenging and time-consuming. Terrain and weather complicate virtually all sustainment operations including logistics resupply, medical evacuation, casualty evacuation, and Soldier health and hygiene. Network of restrictive mountainous roads often does not support resupply vehicles with large turning radius, or permit two-way traffic. Movement of supplies often involves a combination of movement types including air, vehicle, foot, and animal, with each technique having its own challenges in mountainous environments.
  • Operations in thinly populated areas. Populace in typical mountainous environments mostly live in small villages in valleys, with some scattered villages in upper mountainous areas. Although farmers and animal herders make up a large majority of the indigenous population and may work higher up in altitude, the vast majority of mountainous terrain remains unpopulated.

Next: 2-58: Tunnels and Caves

Go Back To: U.S. Army FM 3-21.8: The Infantry Rifle Platoon and Squad