Portrait of the photographer of the U.S. 10th Mountain Division, David B. Allen, in front of the door to a barracks, 1944. He is wearing a cap and a field jacket and is standing in such a manner that the Tenth Mountain Division insignia, "the mountain patch" on his sleeve faces the camera. The 10th Mountain Division ACU patch features a powder keg shaped background with two bayonets crossed upwards. The bayonets are symbolic of infantry while the position of the bayonets simulates the numerical designation of the organization. The shoulder sleeve insignia was originally approved for the 10th Light Division on 7 January 1944. It was designated for the 10th Mountain Division and a mountain tab was added on 22 November 1944. Although the proper branch insignia was crossed bayonets, some 10th Mountain Division soldiers in the three infantry regiments and one reconnaissance troop of the division wore crossed skis, often with a small US, eagle, or regimental number placed over or under the skis' intersection. Officers and some enlisted men wore the ski insignia above the left pocket, although a larger insignia intended for wear like a badge. Many enlisted men also wore the ornaments on the cap.
Book "Encyclopedia of United States Army Insignia and Uniforms" by William K. Emerson