TULSA, Oklahoma - Tulsa's Gilcrease Museum has hosted exhibits for 65 years and now it's expanding with a new state-of-the-art center.

It'll be called the Helmerich Center for American Research and will hold one of the world's largest collections of art, artifacts and archives relating to the Americas.

It's doesn't open until this spring, but you can get a sneak-peek this weekend.

The 26,000 square-foot, $28 million project is the brainchild of Thomas Gilcrease, an Oklahoma oilman who left behind a large collection of art and archives.

"He wanted to share this collection with the world and this is just another extraordinary avenue to do that,” said Gilcrease Museum's Interim COO, Susan Neal.

The collection includes more than 100,000 manuscripts, rare books, maps and letters that tell the story of the Americas.

Among the documents, the only certified handwritten copy of the Declaration of Independence, signed by Benjamin Franklin.

Most of the time the archives are secured in storage and a copy is placed on display, but during select times throughout the year they're brought out here for everyone to enjoy.

"We are very concerned with how we manage our environment here, we have special controls on our heating and air conditioning systems,” Associate Conservator, Ann Boulton said. "We have special filters on all our light fixtures and our windows in order to block out UV light which is also very damaging."

Boulton restores and preserves some of the most valuable documents at Gilcrese. She's currently working on one of the earliest forms of photography in a brand new preservation room.

"Our paper collections are housed in acid free folders, acid free boxes, all of these things help preserve,” Boulton said.

Many of the rare documents are also placed in safes that require both a key lock and a combination lock to access.

"I don't believe that there is any preservation lab in the state of Oklahoma like this,” said Neal.

It's a one-of-a-kind center in Tulsa, and it's now available for the world to discover.

"Rediscover Gilcrease" is free and it gets started Saturday morning at 10:30. Visitors this weekend will also be able to see some rare works of art that have been kept in a vault for two decades.

The funding for the new research center came mainly from Helmerich Family Foundation and some private donations also helped.