Some 80 years ago this month, members of the intelligence and reconnaissance (I&R) platoon, 86th Mountain Infantry Regiment, 10th Mountain Division, logged the first documented combat use of ski troops by the American military as they sent patrols over the snow-covered Campiano-Mancinella Ridge, also known as Riva Ridge, to scout the German positions there overlooking Mount Belvedere.

Sgt. Stephen P. Knowlton, Durham, N.H., I & R Platoon, 86th Mountain Inf., 10th Mountain Div., does a couple of short turns to get his “ski legs” as he prepares to leave on a 3-day ski patrol deep into enemy territory. 21 January, 1945. Spigvana, Italy. Graning, 3131st Signal Service Co., SC 201357
As detailed by the Army:
Five Soldiers were sent on a mission to report on the location and enemy strength on the ridge. The team used skis but hid them away before reaching the top. The men free-climbed to the top of the cliff. The men took out three German soldiers but were chased from the area by machine-gun fire.
“From then on, there was increased activity on the ridge,” wrote Lt. Col. Henry J. Hampton, who served as commander of 1st Battalion, 86th Infantry Regiment during the operation. “There was continual improvement and digging of old and new positions. The result of this patrol was that we had one trail over which a small force of well-trained mountain men could advance.”

“A 5-man ski patrol of the I & R Platoon, 86th Mountain Inf., 10th Mountain Div., begin to climb up the mountain as they start deep into enemy territory on a 3-day patrol, the longest one ever made in this region. All 5 men are famous skiers and have held records at one time or another. 21 January 1945. Spigvana, Italy.” Photographer: Graning, 3131st Signal Service Co. SC 201358

Two GIs with the 10th Mountain Division in the Apennine Mountains Italy, likely early 1945, Note the snow camo, Ray Bans, and mix of M1 Garand (front) and M1 Carbine (rear). LIFE Magazine Archives – Margaret Bourke-White Photographer WWP-PD
Simple origins
Formed following reports of wildly successful Finnish ski troops in the 1939-40 Winter War, FDR stressed that something similar could be established from U.S. soldiers, with experienced men drawn from among the estimated 2 million Americans who enjoyed the winter sport in the States.

U.S. Army Takes to Skis, 1/14/1940 Lake Placid, N.Y.—Perhaps taking a lesson from the Fighting Finns who glide swiftly over the snow to cut down unwary Russians. Men of the 26th Infantry, U.S. Army, stationed at Plattsburg, N.Y., slide along in single file as they receive ski instruction at Lake Placid from Rolf Munsen, Olympic star. Credit: ACME;
Formed beginning in November 1941 by blending earlier ski troop detachments from the 1st, 3rd, 5th, 6th, 41st, and 44th Infantry Divisions, then greatly expanded by volunteers from other units who attested to peacetime alpine experience, the 10th Mountain remains the only American military division recruited by civilian organizations, the American Alpine Club and National Ski Patrol.
The training cadre was drawn from the Ski Patrol itself and included many American winter Olympians.
These American ski troops got lots of press in 1943 during training.

Famous image of Corporal Hall Burton, Mountain Trooper, At Camp Hale, Colorado, ca. 1943 10th Mountain M1 Garand ski 111-SC-329331

World War II American soldiers on skis take aim with M1 Garands during winter training in the Colorado Rockies 10th mountain
Following something of a dress rehearsal in the liberation of the Aleutians, the 10th arrived in the North Apennines and the Po Valley front on 6 January 1945 and went into tough combat, earning their motto “Climb to Glory” in the hardest of ways.
During its brief four months in combat, the division suffered a staggering 4,866 casualties– a full quarter of its strength. This average of 1,216 casualties per month was the highest in the Italian campaign.
While ISR platoons in other American infantry units were issued skis and told to make a go of it as best they could (see the slapstickyness below), only the 10th actually sent patrols out on the devices.

60th Infantry Regiment, 9th Infantry Division – 12 January 1945. Wearing Quartermaster-issued snow capes, American soldiers go into training as ski troops. Lt. William M. Trafford, left, of Vinal Haven, Maine, gives instructions to one man while others look on. L-R: Pfc. Donald L. Taylor, Devils Lake, N.D.; Cpl. Edmund J. Hums, Jr., Pottstown, Pa.; Pvt. Ernest Bassett, Pittsfield, Mass.; Pfc. Glen K. (illegible), Ypsilanti, Mich.; and Pfc. Alfred J. Peters, Buffalo, N.Y. SC 199088-S