A product of the late ice age, the glacier looked old and tired on this hot day. There was a sense of loss, some people said, at watching this giant recoil. There were oohs and aahs but also more hushed tones, expressions of fear that the big land was somehow diminished, a little less wild. Just a few years ago, the spot where these tourists stood, on dry ground marked by Park Service signs, had been under ice.

Alaska is changing by the hour. From the far north, where higher seas are swamping native villages, to the tundra around Fairbanks, where melting permafrost is forcing some roads and structures to buckle in what looks like a cartoon version of a hangover, to the rivers of ice receding from inlets, warmer temperatures are remaking the Last Frontier State.

That transformation was particularly apparent at the visitor center here, where rangers were putting the finishing touches on a display that sought to explain the changing landscape of the country's northernmost state. The sign said, "Glimpses of an Ice Age past. Laboratory of climate change today," and it explained how the Exit Glacier has been shrinking over the years, and what scientists are learning as the state heats up.

Out in the fjords, kayakers paddled into bays newly opened by other receding glaciers. They came to see the ice, a tour guide explained, to paddle around something that had been moving toward a tidewater destiny for thousands of years. And many of them were in a hurry. Glacial pace, in Alaska, no longer means slow.

"Things are melting pretty fast around here," said Jim Ireland, the chief ranger for Kenai Fjords. Climate change, he said, "has become one of the major new themes for this park."

In ambition, in the scale of its scenic extremes, in the pure size and wonder of its fish and wildlife, Alaska has never been anything less than flamboyant. It is, after all, more than two times the size of Texas, with a shoreline, more than 33,000 miles, that exceeds that of all other states combined. And as Alaska morphs through a period of warmer weather, it is doing so with characteristic extravagance.

The old Alaska, the Alaska of forbidden expanses and adrenaline-surging encounters with brawnier ends of the food chain, still exists of course. But a larger drama - of this land losing some of its icy inheritance - is playing out as well.

The sea-level edge of the Exit Glacier, just outside the town of Seward and one of the most visited bodies of ice in the north, has receded by nearly 1,000 feet over the last 10 years, park rangers say. In Prince William Sound and farther south in Glacier Bay National Park, where the cruise ship industry does a thriving business based on active walls of ice, many glaciers have pulled their toes out of the water and shriveled up the valleys. This process has created another attraction: the instant landscape. Take away the ice, add rain and sunshine to the debris left behind and, presto, Stage 1 of creation.

To some visitors who fear that global warming is to blame for the accelerated pace of change, there is a sense of urgency in their travel planning. They seem to be fearful that if they don't get to Alaska soon, they will never see the full glory of the state's frozen magnificence.

"One of the things we hear a lot from people is that they want to see Alaska before it's gone," said Hugh Rose, a tour guide, geologist and photographer who lives in Fairbanks. "The melting, the warmer temperatures, the changing patterns of wildlife and the land - they've become huge topics of conversation among guides and our clients."

Of course, Alaska is not going anywhere, at least not right away. About 4 percent of the state is ice. One glacier, the Malaspina, is larger than Rhode Island, and another, the Harding Icefield, which feeds the Exit Glacier, is nearly half that size. If all of Alaska's glaciers were joined in one mass, it would be bigger than 10 of the states.

But the Great Land is definitely getting warmer. Last year was abnormally hot in the usually wet and cool southeastern part of the state, where cruise ships ply the Inside Passage. Anchorage, Fairbanks, Nome and Juneau all posted their warmest summers on record. More wildfires burned in 2004 than any other year on file. And by early May of this year, the woods were ablaze on the Kenai Peninsula, and the preternaturally quirky residents of Homer were gardening in cutoffs - at a time when snow was still falling in Detroit and Boston.

This year, Mr. Rose noticed something odd during the annual spring birding trek he leads to the Copper River Delta, famous for its rich, high-priced wild salmon runs. He takes people to the delta to watch masses of western sandpipers that have migrated north from winter havens in Central and South America. The birds, and people who pay to watch them, have brought an infusion of tourism cash to the fishing village of Cordova, which highlights the migration with an annual shorebird festival. The event has traditionally been held on the second weekend in May; last year it was moved to the first weekend of the month. "There used to be 100,000 birds on the second weekend in May," said Mr. Rose. "Now you'll miss most of them if you don't arrive earlier."

The question of exactly how much warmer Alaska is than "normal" - and whether it is part of human-caused changes in the temperature brought on by increased greenhouse gases or something natural and cyclical - can start a decent bar fight in any fishing harbor.

"It is probable the last decade was warmer than any other" since records have been kept, the Arctic Climate Impact Assessment reported on Nov. 24, 2004. The study is a project of nations including Denmark, Canada and the United States. The Bush Administration, which has been cautious about blaming global warming for any Alaskan changes, cites rising spring temperatures, loss of sea and glacial ice, melting permafrost and conversion of some parts of the soggy tundra into brushy wetlands among the changes taking place.

But to many Alaskans, global warming is not an abstraction or a theory. At least four native villages in the far north may have to move inland or to higher ground to avoid being swept away by erosion from the sea - a consequence, the villagers say, of early-melting sea ice that contributes to shore erosion. The melting ice may also affect polar bears, and whales, who live off the sea life beneath the ice.

None of this has deterred people from coming to Alaska. If anything, say many guides and tour operators, warming temperatures have brought more people, and the Alaska Travel Industry Association is projecting a strong year, surpassing last year's 1.45 million visitors. And while travel industry officials say they are not exactly marketing the warmer temperatures around a "See Alaska Now" campaign, they say some travelers are driven by concern about the fate of the Great Land in a warmer world. "Our clients are really interested in this," said John Page, who runs Sunny Cove Sea Kayaking Company in Seward. "Everyone wants to know: Is the ice retreating because of global warming? How's this going to change Alaska?"

For tourists, it can mean a thrill at seeing a landscape more dynamic than any place on earth - global warming on hyperspeed! - or disappointment that something so wild and massive is, well, shrinking.

Both reactions were evident at Portage Lake, about 50 miles south of Anchorage. Tour buses packed the parking lot of the big, well-staffed Begich, Boggs Visitor Center. This is where people come by the thousands to see Portage Glacier, one of the most accessible of Alaska's frozen attractions. Except, you can no longer see Portage Glacier from the visitor center. It has disappeared.

The most persistent question to rangers at the station was: Dude, where did Portage Glacier go? A display inside showed that just 11 years ago, the glacier descended down to the end of the lake. But now it is around a distant corner and at the back of the lake, completely out of sight from the center. A video featured a Forest Service scientist, Kristine Crossen, who explained that the glacier had been retreating about 165 feet a year. "We have good evidence that the climate is warming in Alaska," she says.

Visitors were perplexed. Gordon Middleton drove up to Portage Lake in his camper, from his home in Anacortes, Wash. He is retired from a life on factory floors and fishing boats. For him, ice is the draw.

"I've been watching glaciers so long I'm called the Ice Man by some of my friends," said Mr. Middleton. He aimed his camera across the lake from a roadside perch and zoomed in, looking for Portage Glacier.

"It's supposed to be ... there," he said, pointing to a shoreline of rocky moraine, the detritus left behind by retreating ice. "But I don't see anything."

Virtually every visitor center built around a glacier or a blue wall hugging a mountain cliff has its landmarks to warmer temperatures. Just outside of Juneau, the Mendenhall Glacier, which is about 12 miles in length, has gradually pulled away from near the parking lot and up the lake. It is still a prime visitor site for people who are bused from cruise ships in port. But for some cruise passengers who have seen the glacier before, the changes are stunning.

"I saw the Mendenhall Glacier 25 years ago, and it has really pulled back since then," said Mark Stringer, who is from Arizona and was visiting Alaska by cruise ship. "But you know, this is a dynamic process. It's a blip in time. We don't know what's going to happen."

In Glacier Bay National Park, the ice has been shrinking since at least the time of Capt. George Vancouver's visit, more than 200 years ago. What are now bays filled with whale-watching kayakers and iceberg-viewing cruise passengers were full of glaciers in the late 1700's, officials say. And what was once bare rock at the edge of the ice to Captain Vancouver's crew is now part of a lush rain forest. But the pace of ice age retreat has greatly accelerated in recent years. Government photos show that Muir Glacier, one of the park's prime attractions, has receded by more than five miles in the last 30 years.

"The big story around here is the retreat of Muir Glacier," said Dave Nemeth, the park's chief of concessions. "But all around the park, there are constant changes going on."

For many amateur photographers on a first visit to Alaska, the money shot is a glacier calving into the water. And with these tidewater glaciers disappearing from places like Prince William Sound and Kenai Fjords, it has prompted some urgent travel advisories for people to hurry before those shots disappear.

"If you ever wanted to take an Alaskan cruise to see glaciers, do it sooner rather than later for the best views," wrote Bob Martin, who runs a Web site called the Inquisitive Traveler.

But people in the cruise ship industry say it is hard to gauge exactly how many visitors are coming to Alaska now out of a sense of concern that Alaska is melting away. "We know glaciers are one of the top five reasons why people travel to Alaska," said Noel DeChambeau, a marketing director at Holland America, the cruise line company. "They want to see natural wonders. And I don't get a sense that the natural wonders are going away any time soon."

But Mr. DeChambeau did note that Holland America's overland trip to the Arctic National Wildlife Refuge, which Congress and President Bush plan to open to oil drilling, sold out early this year. Other tour operators also report a surge of interest in travel within the Arctic Circle.

"Some people are clueless or they say, 'Cool - your summers are getting longer,' " said Mr. Rose, the Fairbanks guide who leads tours to the Arctic. "But for every one of them, we get a client genuinely concerned that Alaska is changing too quickly, and they want to see it while they can."

In the town of Seward, which seems to have a disproportionate number of people who dine with baseball hats emblazoned with a fishing hook and the slogan "Bite Me," residents are of two minds about the warming weather.

Up at Exit Glacier, a man who told everyone his name was Pete and said he lived in Seward was holding forth, telling people that just five years ago he could reach out and touch the glacier from where he stood, a good 300 yards from the edge of the ice now.

Meanwhile, back in town, tour guides were doing a brisk business during a week when people were wearing Hawaiian shirts and lathering on the sunscreen.

"I've lived here 22 years, and the changes I've seen are tremendous," said Mr. Page, the Seward kayaking guide. "The summers are much warmer and sunnier. We see things like white-sided dolphins, which don't normally appear in these waters. It certainly has not hurt business. But on a planetary level, I'm concerned."

Other Alaskans are trying to take the long view - enjoying the rush of visitors to see a land shaking off much of its frozen past.

"I'm 64 years old so I'm not too worried it's all going to melt in my time," said Charlie Clements, who runs the Blue Heron B & B, in Gustavus, just outside Glacier Bay National Park. "But I have noticed a lot of changes. We aren't getting as much snow. And the summers, they've been really warm."

His bed-and-breakfast, which is planted in one of the wettest places on the planet, within miles of some of the world's biggest glaciers, now has an added feature: a sunroom. It is no longer a joke.