Whether the shot went errant, or the fatal strike missed its mark and the prey shook free the weapon, the hunter never retrieved his spear-like dart. For more than 10,000 years it rested on a windswept mountainside not far from Yellowstone National Park. Then, late in 2007, Craig Lee spotted the branch-like dart shaft in the debris of a melting ice patch.

“I looked down there and I could see, ‘That’s it!’, Mr. Lee recalled last week. “It was absolutely amazing. The adrenalin was pumping, I was really excited. I took I don’t know how many photos from every different angle as it was lying there, and got a couple of awesome GPS points on it.”

The archaeologist’s find demonstrates how national parks, long treasured as windows into our past, are proving to be better time capsules than we might have imagined just a decade ago.

The piece of birch branch, roughly 42 inches long, was the “foreshaft” of an atlatl, a prehistoric weapon mastered by paleoindians in hunting bison, mountain goats and sheep, deer, and other wildlife. Its discovery by Mr. Lee, a research associate at the University of Colorado at Boulder, is just the latest treasure from the past discovered in national parks where climate change is melting back ice and snowfields and uncovering both prehistoric and historic artifacts.

In Wrangell-St. Elias National Park, a team of researchers that included Mr. Lee, in the early 2000s found “prehistoric bows and arrows, spears, hunting tools, baskets, clothing, and even human remains.” Later this summer, a multi-year survey will get under way in Glacier National Park, with the assistance of the Salish, Kootenai, and Blackfeet tribes, to see what glimpses into the past climate change might be revealing in that glacial landscape.

Stories told in the debris field of retreating snow and ice can be fascinating, as the work done in Wrangell St.-Elias and now near Yellowstone proves. The history in these wakes is not always chronological.

The melting “forms a lag deposit where you can get a lot of different materials from different time periods,” Mr. Lee explained. “Consequently, if you want to figure out the story or the scenario or figure out at what points in time people were using this location -- or at least at what points they were losing artifacts -- and you’re finding them, you almost have to date everything.

“There’s a good example from the work with Jim Dixon in Wrangell-St. Elias National Park where we found an arrow shaft in relatively close association, maybe a dozen feet away, from a barbed antler projectile point,” he said. “And the logical assumption is that the arrow and the arrow point go together. But in reality, we radio-carbon dated it and they’re about 600 years apart in age.”

It was his work in Alaska, and his knowledge of the landscape in and around Yellowstone gained from growing up in Montana, that led Mr. Lee to search the alpine reaches that rise around the national park. Using a Geographic Information System model that he and colleagues had developed over the years by blending topographic information with wildlife ranges, the archaeologist honed in on areas he considered promising for holding ancient artifacts.

While it would have been nice if he could have used a helicopter to reach these backcountry sites that lie within national forests, Mr. Lee was limited both by funding resources and the fact that many of the sites he wanted to inspect where in officially designated wilderness areas that prohibit helicopter landings. While the U.S. Forest Service on occasion has pack trains heading into the backcountry, “they generally have a fire priority, and the time of year when we do the survey of course is when fires are going on, it’s later season stuff, so that’s never worked out,” said Mr. Lee. “And unfortunately I start butting up against the hunting season, and the (outfitters) are wanting to start laying in their camps and their horses are pretty much committed, they don’t want to take some researcher.

“So I just figured that it’s easier to get in on feet.”

While the archaeologist, who on occasion has hiked upwards of 40 miles to a site, discovered the foreshaft late in 2007, the find wasn’t announced until last week due to the time it takes to get radio-carbon dating completed. Although the researcher fully expected to find something in the region, he never entertained the thought of finding something 10,400 years old.

“The thing that’s the jaw-dropper is the age on it. The thought was that, ‘Oh, maybe we’ll find something that’s more recent, along the lines of 300, 500, maybe even, wow, 1,000 years old,’” said Mr. Lee. “For instance, at this point the oldest thing that’s been recovered from snow and ice in Alaska, in Wrangell-St. Elias and some of the other parks that have been looked at, it’s just about 3,000 years old, so you wouldn’t necessarily have the expectation that you’re going to find something exceptionally ancient.”

Another fascinating aspect of the discovery is that the shaft bore markings that could have been the hunter’s way of identifying his weapons. Three parallel marks can be seen on both sides of the shaft, said the archaeologist.

“So he threw the whole armament and managed to get the foreshaft to penetrate the animal and if the animal managed to break off the end of the shaft somehow and the point stays in it, then when you catch the animal and then you recover it you basically can see based on those marks whose shot it was,” said Mr. Lee. “The things that come up, then, well, does this represent communal hunting? Why would a person need to mark their weapon?

“I think that communal hunting is a good scenario to think about. ... It’s hard to really say how meat-sharing practices and those kind of things maybe went on 10,000 years ago,” he said. “Generally in hunter-gather groups people share quite well; it’s in their best interests to share things.”

Though it’s impossible to know what the hunter was trying to kill, the archaeologist ventures he was stalking sheep.

“I think it’s probably sheep in this location, although we’ve found remains of everything. We’ve got elk, we’ve got bison, certainly sheep, mule deer,” he said. “I think there could be a variety of animals that show up based on the faunal material, the butchered faunal material that was in the area that does not date to the same time period as the dart foreshaft. But there is some butchered faunal material in this area that appears to be sheep. So I think that mountain sheep make a lot of sense.”

With climatic warming under way, and the prospect that more retreat of ice patches, snowfields, and glaciers will occur, it’s not far-fetched to expect more artifacts to be exposed in the National Park System. Glacier National Park is a perfect setting for such a scenario to play out.

“Perhaps nowhere else in the U.S. is the evidence for climate change more apparent than in Glacier National Park. The park, which contained over 150 glaciers in 1910 at the time of establishment, now contains only 26 glaciers—a reduction of about 67 percent,” said Glacier spokeswoman Amy Vanderbilt. “As a group this is the fastest glacial recession of any glaciated region in the lower 48 states, and we've all heard that experts predict that all of the glaciers in the park could be lost by as early as 2020.

“Newly exposed artifacts and natural items with unique scientific and cultural value are threatened by loss or destruction,” she continued.

While poaching of such artifacts always is a possibility, Park Service officials believe the remote location of such deposits, as well as normal backcountry patrols, will work against poachers.

“We don't disclose locations that might be subject to artifact poaching and/or damage,” said Ms. Vanderbilt. “Rangers do the best they can to patrol the high country and investigate leads when/if they receive them.”

In Alaska, “the good news is that in Wrangell-St. Elias and Lake Clark and we think Denali (it has not come to light yet due to limited surveys) it is difficult to find for only 10 percent or so of the ice patches possess the items,” said Ted Birkedal, the Park Service’s chief of cultural resources for the Alaska Region.

The discoveries at Wrangell-St. Elias involved visits to 300 far-flung ice patches before 30 containing artifacts were found, said Chief Birkedal.

“These things are usually found at 3,000 feet and above. There will be somebody who might purposely find the right ice patch once in a while, but it will be fairly rare," he said.

Mr. Lee has not disclosed the exact location of his discovery, simply so there won’t be a rush of artifact poachers to the area.

“How many of these ice patches down in the mid-latitudes are going to contain archaeological materials? Do we have to be cautious with that kind of information with the public, for fear of having a stampede?” he wondered. “I mean, one of the articles I saw (recounting his discovery), I was a little bit saddened by it because they made the analogy to looking for gold and treasure and all this kind of stuff, which is not what we’re doing.”

Editor's note: The following video released by the University of Colorado contains footage the National Geographic Society assembled during ice patch field trips Mr. Dixon and Mr. Lee led into Wrangell-St. Elias and Lake Clark national parks.