Like other remote, "exotic" lands, the vast expanse of mountains, forests, tundra, wild streams and endless, rugged shoreline known as Alaska has long fired the imagination of millions who have never set foot there. Just as mind-boggling as the 49th state's spectacular (if sometimes harsh) beauty, however, is that fewer than three-quarters of a million people call the state's 660,000 square miles home. In other words: Alaska has about one resident per square mile; New Jersey, by comparison, has about 1,200 inhabitants per square mile.
Get the picture? The place is huge, and even after all these years as a U.S. territory and as an exporter of key resources (primarily oil, abut also seafood, timber, minerals and more) it remains relatively empty.
Of course, different parts of what is now Alaska have been occupied by various peoples for thousands of years, long before Europeans and, from the other direction, Russians began arriving in significant numbers a few centuries ago. And yet, after many hundreds of years and several waves of immigration, the fact that Alaska still holds far fewer than a million people is rather astonishing — and in many ways, adds to the Last Frontier's mystique as a bastion of hardy, rough-and-tumble, solitude-loving homesteaders scraping a living from the land, rivers and sea.
(That Alaskans receive more federal aid per capita, in relation to taxes paid, than the citizens of almost any other state is something that isn't celebrated quite as loudly as that can-do, pioneer spirit.)
Here, on the 100th anniversary of Alaska becoming an American territory (it was proclaimed a state in January 1959), LIFE.com presents pictures — many of which did not run in the magazine — made by photographer Ralph Crane for a major cover story in 1965.
As LIFE put it in the introduction to the piece:
Alaska, the 49th state, is also the largest, most forbidding and least understood. Its 250,000 people [Note: now three times that number] are suspended, a bit uneasily, between memories of a pioneer, hardscrabble past and dreams of a glittering, prosperous future. The photographs [here] explore this hostile and demanding land which seems to conspire against man even as it engenders and commands his fierce loyalty.
Though some of the pioneers [who built Alaska] were simply moving out of range of the sheriff, and others would be misfits anywhere, most of them were the kind of men whose hearts beat faster out of doors, who drew strength from the struggle with nature ... folks who just wanted to get away from the confines of the onrushing civilization.
Five decades after those words were written, Alaska still retains a good deal of its allure as a place outside of both time and beyond the the strictures and constraints of "the lower 48."
Liz Ronk, who edited this gallery, is the Photo Editor for LIFE.com. Follow her on Twitter @lizabethronk.