Former Marine infantryman Lance Blyth was having “one very miserable day” out on Tennessee Pass near Leadville backcountry skiing.

He recalled the snow on that day as unsupportable, so with every stride on his skis he punched through 6 to 8 inches. It was tough going and the sweat in the cold temperatures soaked his gloves and then froze his hands.

Looking down at Camp Hale from his trek, he wondered how the troops in the famed 10th Mountain Division learned to deal with similar conditions.

The 10th Mountain Division trained at Camp Hale in mountain warfare techniques before deploying to Italy in late 1944. After the war, some members came back and helped establish Vail and Aspen as ski destinations.

While the division is highly celebrated and chronicled in Colorado, Blyth wondered how they learned to ski, bivouac, and climb — details not covered in other histories.

His questions led to the book “Ski, Climb, Fight: The 10th Mountain Division and the Rise of Mountain Warfare,” which published at the end of last year.

Blyth’s look at the famed division also describes how civilian expertise and gear helped inform mountain warfare.

“That’s really unique in military operations,” said Blyth, who is the Command Historian of the North American Aerospace Defense Command and the U.S. Northern Command.

For example, Jim Whittacker, the first American to summit Mount Everest, was an instructor at the Mountain and Cold Weather Training Command based at Fort Carson during the 1950s.

Blyth, like other historians, drew some of the material from the letters and papers that the veterans of the division donated to the Denver Public Library in the 1990s. Many of the divisions soldiers had been to college and the group sustained a relatively low number of casualties during World War II, so the troops’ exploits are well documented.

Many of the senior leaders of the 10th Mountain Division went on to teach at the Mountain and Cold Weather Training Command at Fort Carson after World War II.

The book goes beyond the history of the division to cover the development of mountain warfare and the necessary training doctrine and equipment through 2023, he said.

For Blyth, mountain training is valuable because the military needs to be prepared for any future challenge and mountains often mark borderlands and points of conflict.

It’s training that takes a year to prepare for summer and winter conditions. Even in July, you can face hypothermia.

“If you can dominate in the mountains, you might find yourself with an advantage,” Blyth said.