
During WWII the US Army organized its first mountain troops, eventually expanded into the 10th Mountain Division. It consisted of skiers, mountain climbers, woodsmen, hunters and other outdoor types. Originally, you had to get a letter of recommendation to get into the division stating that you had some qualification the unit needed.
The climbers were issued with all the latest equipment, including these type 5 soft iron pitons. These were hammered into cracks in the rock to anchor climbing ropes.