Long after his death we continue to celebrate the brilliance of Ansel Adams, who arguably defined landscape photography, often while working in national parks to capture the magnificence of nature.

Even today, more than a quarter-century after his death, there's a steady clamor for the photographer's images. When word broke earlier this year that an overlooked cache of his negatives had been found at a garage sale, it became national news...and sparked more than a little controversy over the authenticity of those glass slides.

Why are Mr. Adams' images so enduring? Is it because of their composition, or because of the time capsules they represent? Is it both?

No doubt much of the allure for an Adams print can be explained by citing the photographer's own words, those he wrote in 1950 in an introduction to his book, My Camera in the National Parks:

The dawn wind in the High Sierra is not just a passage of cool air through forest conifers, but within the labyrinth of human consciousness becomes a stirring of some world-magic of most delicate persuasion. The grand lift of the Tetons is more than a mechanistic fold and faulting of the earth's crust; it becomes a primal gesture of the earth beneath a greater sky. And on the ancient Acadian coast an even more ancient Atlantic surge disputes the granite headlands with more than the slow, crumbling erosion of the seas. Here are forces familiar with the aeons of creation, and with the aeons of the ending of the world.

While there are numerous books, posters, and postcards where you can see how Mr. Adams transformed those words into images, there's a new one coming out in time for your holiday wish list that contains more than 200 of his images -- 50 of which previously were unpublished.

Ansel Adams In the National Parks, a 344-page hardcover book, is a great addition to any park lover's bookshelf, as well as to the library of any art lover. It contains many of his well-known images, such as that of White House Ruin in Canyon de Chelly National Monument and the iconic shot of the backdrop of the Tetons with the serpentine Snake River in the foreground shot in Grand Teton National Park in 1942.

But it goes further than that.

Adding to the figurative heft of this book is that it was edited by Andrea Stillman, who worked for the photographer in the 1970s, and contains original essays by critic Richard B. Woodward, insights the late Wallace Stegner wrote in a forward to an earlier Adams book, family photos that show Mr. Adams working in the parks -- and enjoying them much like any other tourist -- as well as other personal notes and quotes that further our knowledge of Mr. Adams when it comes to his approach to photographing landscape as well as his interpretation of nature.

For instance, of that 1942 shot of the Tetons, he notes that, "This is one of a sequence of five photographs of the Tetons in a thunder storm. All were made with rather ample exposure and development in order to assure rich values in the clouds and shadowed areas. As no blue sky shows, the effect of the K2 yellow filter was only to clarify the distance, as there was a slight haze over all."

And then there were these impressions he shared with an assistant, Patricia English, after visiting Carlsbad Caverns:

I am gradually becoming impressed with the Carlsbad Caverns; they are so strange and deep in the earth that I can never feel about them as I do with things in the sun -- rocks, trees ... surf and fog. The photographic problems are terrific; I start with a basic exposure of about 10 minutes...I then boost up the image and "drama" with photoflash. Some of the forms are beyond description for sheer beauty...Twice a day I ride down in the elevator (just like an office building) for 750 feet, and then walk a mile through the caverns to the selected spot...Today the elevators were not working in the morning and I carried the camera, tripod, reflector and lights all the way down the trail for the full 750 feet. My shoulders are a bit creaky tonight.

Through Mr. Woodward's contributions we learn that Mr. Adams hated to use manipulation to achieve his photographs.

Always concerned about violating his own principles of 'straight photography,' Ansel was especially concerned that his sleight-of-hand manipulation -- a double exposure designed to exaggerate the size of the moon -- might represent a moral and artistic transgression. Speaking for both, (friend) Beaumont (Newhall) wondered: "Where is the line between double exposure (as made by Stieglitz in his night views of skyscrapers) and combination prints (as made by [Henry Peach] Robinson)?

And we learn from Mr. Woodward that the photographer was like any other freelancer, always looking to make one job pay twice, or thrice.

As the Guggenheim stipend (for photographing national parks in 1947 and 1948) would not come close to paying all the bills for himself, his family, and a transcontinental three-year project, Ansel had lined up commercial assignments from magazines (Fortune and Life were clients) and companies (Eastman Kodak). As he traveled through the national parks, he would often make photographs in color and black-and-white of the same prospect, the color pictures to satisfy his clients.

But Mr. Woodward's writings go beyond that. In one back-of-the-book essay, Ansel Adams and the Preservation of Wilderness, he zooms away from his tight focus on Mr. Adams to the larger subject of how photography and photographers became "innately allied with maternal forces of preservation."

Cameras are in the sealed chambers of their hearts instruments for conserving the past. Each moment caught in one of these light traps is unique. Whatever the camera is aimed at, from a landscape out a car window to a rare specimen of life, may be saved and recalled for study later. As our sense of what happened yesterday or decades ago is often as muddled and contentious as our plans for the future, a mechanical process that provides more or less realistic evidence of the world as it once was can be of immense practical and political value.

While Mr. Adams is of course the heart and soul of this book, Mr. Woodward notes that "other photographers contributed to the emerging idea that America's natural resources were exceptional and should be preserved in a thoughtful fashion for later generations. The English photographer Eadweard Muybridge, eyeing the accomplishment of (Carleton) Watkins, went to Yosemite in 1867 and made pictures from many of the same places as his predecessor. William Henry Jackson, a Civil War veteran from Keeseville, New York, had accompanied Ferdinand V. Hayden's geological expedition to the Yellowstone region in 1871. Jackson's large-scale photographs of Yellowstone Lake, Riverside Geyser, and Mammoth Hot Springs were widely admired by the public and, together with Thomas Moran's operatic paintings of the area and Hayden's report, influenced the US Congress to create Yellowstone National Park in 1872, the first in the country's history and another milestone in the conservation movement."

While these sidebars of text add richly to the book, it is, after all, the images that carry it. It is the shots such as that of Longs Peak in Rocky Mountain National Park with a broad sweep of forest in the foreground, of a simple jumble of rocks on the floor of Yosemite Valley, of a contorted cactus in Organ Pipe Cactus National Monument, and of the pounding surf at Schoodic Point in Acadia, that make you want to both quickly turn pages and yet linger over each image.

The never-published Ansel Adams photos in this book, 32 in all, are on the following pages: 41, 47, 53, 56, 71, 77, 90, 95, 106, 124, 134, 145, 149, 150, 152, 163, 164, 172, 178, 212, 218, 221, 222, 223, 228, 242 (2 photos), 268, 269, 272, 275, and 296. There are also 32 very rarely published Ansel Adams photos in the book -- photos that were, for the most part, printed in magazines, exhibition catalogs, etc., rather than in books. These rarely seen photos are on pages 34, 52, 54, 61, 64, 69, 73, 75 (3 photos), 83, 112, 119, 121, 125, 128, 138, 139, 142, 146, 159, 187, 195, 199, 205, 231, 252, 255, 277, 285, and 297.