As they looked through the windows of the Kansas University Natural History Museum’s panorama one day this week, several kids asked their parents the same question: “Why are those people in there?”

Behind the glass, next to frozen-in-time grizzly bears, bison and moose, conservators in hazmat suits methodically brushed and vacuumed decades of dust off the 120-year-old, 8,000-square-foot exhibit. They were there not only to clean the panorama but to assess its condition; later, they will provide recommendations on how best to renovate it.

Conservation experts are spending the month at the KU Natural History Museum evaluating the conditions of the 120-year-old panorama, which features North American plants and animals.

Then-Kansas University professor Lewis Lindsay Dyche created the panorama to show at the 1893 Chicago World’s Fair, where thousands of visitors got to observe 121 North American mammals in their natural environments.

In response to the display’s popularity, the Kansas Legislature approved funding for the 1902 construction of Dyche Hall, where the panorama has been housed ever since. The KU Natural History Museum was built around the panorama, its design inspired by a French cathedral with the plant-and-animal exhibit as its apse.

But after decades of exposure to light and humidity, the panorama is in need of a makeover.

“As these mounts begin to fall apart, they create this disconnect between the viewer and the object,” said museum spokeswoman Jen Humphrey. “They begin to see the cracked skins and the faded hides instead of seeing the woodland scene or seeing the animal on the mountain or taking in how big an elk is.”

The preservation project began with a $50,000 “challenge grant” from museum board members Kent and Janet McKinney that was then matched by other donors in the community. In total, about $100,000 is going to fund the conservation assessment.

The assessment started last year, with an analysis of the toxic chemicals in the exhibit because, in the late 1800s, taxidermists used heavy metals to prevent insect infestation. Researchers found arsenic, mercuric chloride and lead (possibly from the background paintings). Thus, the hazmat suits.

A team of conservators arrived in Lawrence earlier this month to spend several weeks cleaning and assessing the condition of the panorama. Ron Harvey, a conservationist with Lincolnville, Maine-based Tuckerbrook Conservation LLC, has been impressed.

“Here in Lawrence, Kan., is one of the oldest and most unique panoramas and dioramas in the world,” he said. “And for the most part, it’s in remarkably good shape given its age.”

How has it lasted so long?

“Part of it was the level and quality of the taxidermy,” he said. “Part of it was luck.”

Harvey explained how in the 1930s, museum officials closed off the skylight above the exhibit because the building was having structural issues. Ultraviolet rays, and light in general, cause the mounts to fade.

The cost and timeline for restoration will be part of the assessment report, which is expected in the late spring or early summer. The museum then will look to the community for feedback and, later, funding.

Museum director Leonard Krishtalka says the preservation is critical because the panorama is the oldest and, from an aerial point of view, largest of its kind, anywhere in the world. It is also, next to Comanche, a horse that survived the Battle of Big Horn, the museum’s best known and most popular exhibit.

“We have generations of Kansans who remember first visiting the panorama, being awed by it and then showing their children and grandchildren,” he said. “It’s been heartening to see the fantastic community support. It’s a recognition that it is indeed one of America’s cultural treasures and one of Kansas’ cultural treasures that needs to be preserved for future generations.”