Turn-of-the-century Alaska was a harsh, demanding, and yet exhilarating place, a landscape that didn't suffer greenhorns. Nineteen-year-old Harry Karstens thrust himself into this setting in 1897 to join the Gold Rush, and went on to cast a long shadow in the state's history, and not just because of his role in summiting Mount McKinley.

Though the book's title hones in on the story of Karstens and his role in that first successful ascent of the 20,320-foot mountain Alaskans refer to as Denali, author Tom Walker has crafted an adventure story that reads a bit like a Jack London novel. But this story isn't fiction.

Rather, it's a story of how young Karstens, fleeing from a bitter fight with his older brother in Chicago, wound up in Alaska to seek his fortune. Fortune he did find, but not in golden ore. While Karstens spent more than a little time prospecting, it was regular work driving a dog sled hundreds of miles through temperatures far below zero to haul supplies, mail, and other miners' ore, that made him a fixture in Alaska.

In the end, he found fame in guiding the first team to reach the very summit of McKinley, in 1913, and a presence as the first superintendent of what became Mount McKinley National Park. Today his name lives on, attached to a ridge high on Denali.

In pulling this story together, Mr. Walker read The Ascent of Denali, the account left behind by Hudson Stuck, who partnered with Karstens on the expedition. But he developed a broader, deeper story by also going through the journals kept by the others on the climb -- Karstens, Walter Harper, and Robert Tatum.

Mr. Walker delved even deeper, tracking down the actual diary that Hudson Stuck had kept on the final push to the summit. Too, he found the journal kept by Tatum, an account Mr. Walker described as the "missing link" to the narrative. It surfaced at the University of Tennessee in the archives.

With those journals, and other personal letters, historical documents, and previous magazine articles and publications, the author has assembled a colorful and insightful story not just of that historic climb, but of life in territorial Alaska.

On every trail, mail teams had the right of way In fact, many trails were open only due to the passage of mail carriers. At roadhouses and shelter camps, carriers got the choice seats at the table, the best food, and the cushiest bunks. They hung their mitts and parkas in reserved spots near the stove and brought their lead dogs inside to sleep under their bunks. Karstens's route from Tanana Crossing to Eagle was almost totally undeveloped. With few exceptions, he was on his own, the only shelter a hastily pitched canvas tent or spruce lean-to that he built himself. Night bivouacs were possible only with a roaring fire and plentiful firewood.

Dog drive, or 'mushing as it was called, as grueling and dangerous. Only the stouthearted and resolute succeeded as mail carriers. All of them had their tales of stabbing cold, raging storms, this ice, overflows, and close calls. They told their stories with missing fingers and toes, and faces blackened by the implacable frost. The price of frostbite was often disfigurement for life.

The book's narrative on the climb of Denali itself vividly describes the hardships the four men endured, how they somehow overcame an accidental fire that burned much of their supplies, of storms that left them tent-bound for days, of physical trials that threatened to block their summit. It also opens a window into the frayed tempers on the mountain and strained egos after the summit, as Stuck initially received much of the acclaim despite Karstens's role not only as Stuck's partner, but in physically leading the four to the summit.

The Seventymile Kid -- a nickname Karstens was tagged with not because of his mushing skills but rather after a river drainage where he thought he would mine riches -- is a rich book of Alaskan history. It details other unsuccessful attempts of the day to reach Denali's summit, provides a dramatic sketch of frontier Alaska, and raises to its deserved prominence the story of Karstens's role in conquering Denali and going on to become the national park's first superintendent, a role he was given in 1921, four years after the park was established.

"...Harry Karstens was appointed ranger-at-large, with an annual token salary of ten dollars," writes Mr. Walker. "His responsibilities included Glacier Bay and Katmai National Monuments, neither of them funded or staffed."

The reputation Karstens earned for his climb of Denali brought him international attention. In 1924, he was invited to join a British team to climb Mount Everest. Karstens, then 44 years old, declined, uncertain "that he still possessed the stamina for high-altitude work," notes Mr. Walker. Two members of that team vanished during the climb; George Mallory's body was found in 1999 on Everest's North Face.

With the centennial of Karstens's summit of Denali arriving this summer, The Seventymile Kid breaths wonderful life into that expedition, and into Alaskan history.