Chapter 1

Mountain Terrain, Weather, and Hazards
Commanders must consider the effects terrain and weather will have on their
operations, mainly on their troops and logistics efforts. Weather and terrain combine
to challenge efforts in moving supplies to forward areas. Spring storms, which may
deposit a foot of snow on dry roads, combined with unprepared vehicles, create
hazardous situations. Helicopters are a valuable asset for use in moving men and
supplies, but commanders should not plan to use them as the only means of
movement and resupply. Alternate methods must be planned due to the variability of
weather. Units scheduled for deployment in mountainous terrain should become
self-sufficient and train under various conditions. Commanders must be familiar with
the restraints that the terrain can place on a unit.

SECTION I. MOUNTAIN TERRAIN
1-1. Operations in the mountains require Soldiers to be physically fit and leaders to be experienced in
operations in this terrain. Problems arise in moving men and transporting loads up and down steep and
varied terrain in order to accomplish the mission. Chances for success in this environment are greater when
a leader has experience operating under the same conditions as his men. Acclimatizing, conditioning, and
training are important factors in successful military mountaineering.

DEFINITION
1-2. Mountains are land forms that rise more than 500 meters above the surrounding plain and are
characterized by steep slopes. Slopes commonly range from 4 to 45 degrees. Cliffs and precipices may be
vertical or overhanging. A mountains may consist of an isolated peak, a ridge(s), a glacier(s), snowfield(s),
compartment(s), or a complex range that extends for long distances and obstructs movement. Mountains
usually favor the defense; however, attacks can succeed by using detailed planning, rehearsals, surprise,
and well-led troops.

COMPOSITION
1-3. All mountains are made up of rocks and all rocks are made up of minerals (compounds that cannot be
broken down except by chemical action). Of about 2,000 known minerals, seven rock-forming minerals
comprise most of the earth’s crust. Quartz and feldspar make up granite and sandstone. Olivene and
pyroxene give basalt its dark color. Amphibole and biotite (mica) are the black crystalline specks in granitic
rocks. Calcite, the only one of the seven that does not contain silicone, is found in limestone.

ROCK AND SLOPE TYPES
1-4. Different types of rock and different slopes present different hazards. The following paragraphs
discuss the characteristics and hazards of the different rocks and slopes.

GRANITE
1-5. Granite produces fewer rockfalls, but its jagged edges make pulling rope and raising equipment more
difficult. Granite is abrasive and increases the danger that ropes or accessory cords will be cut. Climbers
must beware of large loose boulders. After a rain, granite dries quickly. Most climbing holds are found in
cracks. Face climbing can be found, however, it cannot be protected.

26 July 2012

TC 3-97.61

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