Bison will return to Denver on Saturday.

The U.S. Fish and Wildlife Service intends to release 16 of the shaggy beasts in the Rocky Mountain Arsenal National Wildlife Refuge to mark the 104th birthday of the National Wildlife Refuge System.

The animals, coming from the National Bison Range in Montana, will establish a pilot herd on a pasture in the northwestern portion of the refuge to help the Service monitor and evaluate the effects bison have on native short grass prairie and to determine the role of bison in the management of the site.

The Refuge will also play a key part in advancing the Service’s national bison conservation program.

"Bison are one of our nation’s most storied animals," said Mitch King, U.S. Fish and Wildlife Service’s Mountain-Prairie regional director. "The return of bison to the Rocky Mountain Arsenal National Wildlife Refuge signals remarkable progress both in the transformation of this site and in the conservation of American bison."

The public will not be allowed in Saturday to ensure a safe release, but the bison pasture will be added to the public tram tour route beginning in April.

The bison pasture once was part of the Rocky Mountain Arsenal where the U.S. Army manufactured nerve gas, and Shell Oil Company manufactured pesticides.

Now they are in the process of cleaning up this Superfund site and to date, more than two-thirds of the site has been certified clean by the Environmental Protection Agency and State of Colorado. Once certification was complete, the U.S. Army transferred the land to the Fish and Wildlife Service, which officially established the national wildlife refuge. Of the 12,000 acres, 1,400 are designated as bison habitat.

"We are pleased that the success of the Rocky Mountain Arsenal cleanup has enabled the American Bison to return to its native home," said Charlie Scharmann, U.S. Army program manager for the Rocky Mountain Arsenal. "To see wild bison roaming on this land is truly remarkable and we are proud to have played a role in this historic conservation effort."

The bison identified for movement from the Bison Range to the Refuge contain valuable and unique genetic characteristics that the Service has determined important to the long-term conservation of wild bison.

The Service is undertaking a series of bison transfers between national wildlife refuges in Montana, North Dakota, Colorado, Nebraska and Iowa to prevent against a catastrophic loss of key genetic material.