As word-of-mouth spreads, more Yellowstone National Park visitors are dropping by Yellowstone's Heritage and Research Center, just outside of Gardiner, Mont., and the park's North Gate.

The Center is a combination warehouse, library, archive, office and research complex includes 5.3 million cataloged items, such as:

· 3,000 linear feet of historical records;

· 90,000 prints and negatives;

· 20,000 books and manuscripts;

· 300,000 cultural and natural science specimens;

· 35,000 archeological artifacts and

· 10,000 plant specimens.

Open since May 2005, the center has 32,000 square feet on seven acres n a vast improvement over the cramped, 3,000 square foot basement of the old Horace Albright Visitor Center in Mammoth Hot Springs.

"This is like a fabulous dream," said Lee Whittlesey, the park historian. "It is wonderful to have space and room to work," he said.

The Heritage and Research Center is the second largest collection in the National Park Service system n just behind the Edison National History Site with six million items. All told, the Park Service has 105 million items n sparking increased discussion about the need for a national NPS museum. The Coalition of National Park Service Retirees would like to see such a national museum in time for the Park Service's centennial celebrations in 2016.

Technically, the Yellowstone center is more of a warehouse and research archive than tourist attraction, notes Al Nash, spokesman for the park. Visitors can see a history of transportation in the park, prior to 1910, in the lobby of the center, he said.

Public tours of the center are by reservation, said Nash, on Tuesday and Thursday mornings. Yellowstone National Park's Archives access is by appointment only, Tuesday-Friday 9 am n 4 pm. At least twenty-four hour advanced notice is required, but does not guarantee staff availability.

"We're not set up for visitors who'd just like to wander through," said Nash. The emphasis is on working with people who have legitimate research interests and needs n academics, historians, writers and genealogists, he said. The center has a dozen year-round staffers and another 10 seasonal or volunteer workers, Nash added.

Ken Burns, the Public Broadcasting System documentarian who created "The Civil War" and "Baseball" documentaries, has had a researcher visit the center three times, gleaning some 1,000 photographic images for an upcoming series about the national parks.

"I'd say our public usage of the center has doubled since we moved in," said Colleen Curry, the center's curator. "We get daily requests about our photo collection," she said, "mostly by phone and email." Army and hotel records in the center's archives attract both genealogists and historians, said Curry, about 40 a month.

Park historian Whittlesey said his productivity has surged because of the ease of research in the center. He's written two new books, one focused on the history of Indian trails in the region, and another about Yellowstone place names.

Curry acknowledged that the staff get lots of questions from visitors and academics. Generally, the odd questions that stump everyone else are forwarded to Whittlesey. "He generally knows about such things," Curry laughed.