Visitors to the locked-away, security-guarded anthropology collection of Carnegie Museum of Natural History are all greeted with the same simple warning.

"Touch anything and I'll break your fingers," says Deb Harding, a collections manager who for 22 years has tended to tens of thousands of artifacts there.

Only about 3 percent of the 112-year-old museum's total holdings are ever on display at one time, so many of its artifacts are stored at an unmarked warehouse in a commercial district, not open to the public, in the city's East End.

Named after a former trustee, the Edward O'Neil Research Center houses the museum's mammal collection, conservation section and laboratory, and a library of donated books on wildlife.

And, of course, the anthropology section, the main depository of the museum's 100,000-plus ethnological and historical specimens, with a focus on materials from Central Africa, Asia, Australia, North America (Arctic, Southwest, Plains, Northwest Coast), and the Amazon in South America. Another 1.5 million archaeological artifacts are held largely on another floor.

The collections, Harding says, are from "every continent except Antarctica -- penguins don't leave artifacts."

Thousands of stories to tell

Anthropology is the study of people, their behavior, cultures and characteristics. One by one, as Harding opens locked cabinets and drawers with artifacts from ancient to current societies, each one tells a story:

There is an ear ornament by the Urubu Ka'apor tribe in Brazil, made in the 1990s from macaw and cotinga tail feathers and breast feathers from a plum-throated cotinga, held together with tree gum.

A late 19th-century coiled basket from the Yokuts American Indian tribe in Northern California is made entirely from natural colors found in plant material: black from the stem of a maidenhair fern, reddish brown from redbud bark, and hazel colors from willow. The top has tiny top feathers from about 20 male quail.

There are drawers filled with Tokugawa-era (1600 to late 1800s) parade armor -- collected by H.J. Heinz himself during a trip to Japan -- and intricately detailed sculptures of Japanese street scenes carved from ivory.

Thousands of items, thousands of stories, one person to explain just a few.

Harding, 56, is a University of Pittsburgh-trained anthropologist with a bob of gray hair, who booms classical music at her desk some 10 hours a day and wears a T-shirt that says, in Latin, "If I wanted your opinion, I would read your entrails." The materials she watches over all have a common thread, which still excites her after two decades in the giant collections room.

"I'm always surrounded by pieces of human ingenuity," she says, inspecting some New Mexico earthenware pottery. "Who'd ever think you could do something like that?"

Another world

On the outside, the museum world has changed greatly since Andrew Carnegie opened his natural history museum in 1895, adding computer touchscreens, animatronic exhibits and other gizmos to keep visitors engaged. On the inside, it still feels a responsibility to science, which is where the rarely seen collections come in.

"The collection is just like a gigantic library of the history of Earth, the history of life, the history of mankind," says Zhe-Xi Luo, the museum's interim co-director, curator of vertebrate paleontology and associate director for research and collections.

"Overall the museum holds a great treasure -- the history of life -- in trust," he says.

There is also a responsibility to the people who made the artifacts.

The anthropology collection has a "sacred cabinet" of American Indian material with objects considered sacred or sensitive, placed there at the request of the tribes and viewed only by a few. It includes Iroquois false facemasks, stored facing down at request of the tribe, and Hopi kachina masks, stored facing tribal lands in the American Southwest.

The museum has occasionally repatriated objects to tribes, but because most are collected with the tribes' permission, that does not often happen -- with one big exception.

A trader gave the museum a full set of Hopi snake dance regalia in 1899, which was used in a full-size diorama by legendary Carnegie preparator Theodore Mills and was exhibited in the museum for decades. The problem was the dance is so revered by the tribe that it is "not something the Hopi even allow Anglos to attend, let alone have on exhibit in a museum for kids to gawk at," Harding says.

The museum dissembled the exhibit and locked away the artifacts in 1992, avoiding embarrassing media reports only because of that year's long newspaper strike.

But most of what Harding does is keep track of tens of thousands of exhibits, which are all numbered, starting with number 1/1, an Egyptian mummy purchased by Carnegie himself. Once a year auditors come to the room with a random list of exhibit numbers and check on them.

Harding spent most of her undergraduate years volunteering in the anthropology collections at Beloit College in Wisconsin and clearly loves being surrounded by artifacts and the lessons they teach.

"One of the ideas people have is that people farther back were stupid -- or less intelligent, I should say. No, they just had different technology," she says, holding onto an American Indian doll, one of 3,000 filling an entire wall of the anthropology collection room.

"We're building on what they did. If you shoved one of us back into that situation and didn't have those things to build on -- that previous knowledge --we wouldn't do any better."