ST. LOUIS - Some of the most familiar faces from the Gateway Arch grounds are going away for good.

Chief Red Cloud, the animatronic figure who has greeted visitors at the Museum of Westward Expansion beneath the Arch since 1997, will not be a part of the tourist attraction when the museum is renovated.

The entire area around the Jefferson National Expansion Memorial is undergoing drastic changes as part of the ambitious CityArchRiver project.

Many of the biggest changes to the Arch grounds, like the park over the highway, have been known for months if not years. But some of the smaller, more specific changes are just now coming to light.

Chief Red Cloud isn't alone. Three other animatronic figures, familiar to anyone who has brought out of town visitors to the Arch, are getting their walking papers.

The William Clark talking robot, Sgt. Robert Banks, and Charles Barber will truly be history when the new museum is opened in 2016.

"There are probably ten reasons why we decided not to re-use the animatronic figures," said Bob Moore, staff historian at the Jefferson National Expansion Memorial.

"One of them is they're getting old and wearing out. Another is, the technology has really surpassed where we were in the 1990's, when we put the animatrons in.

"Another thing is, the story they're telling, which is the story of the Peace Medals, is not going to be one of the primary focuses of the new museum."

Museum visitors on Friday reacted with a mix of surprise and disappointment that the animatronic figures were going away, while admitting they are a bit creepy.

"I think they're cool, I would definitely miss them," said Cassandra Bechdel.

"In a way, my children have grown up with Red Cloud," said Frank Hogrebe, a father of six from St. Louis. "It seems a shame they won't be part of the new exhibits or that they don't fit into the new concept for the museum."

Is there any chance of saving Chief Red Cloud and his cohorts? Maybe even finding them a new home in another area museum?

"We're not really sure what the disposition of the figures will be," Moore said. "It takes a lot of infrastructure to make them run—behind the scenes—that you can't see here in the exhibit, including compressed air and a lot of things that allow them to move the way they do. It wouldn't be just a matter of another institution taking one of the animatrons and setting it up. They'd have to build quite a bit of infrastructure to actually make them work."

Even so, there could still be a new assignment for these somewhat-living history machines.

"I don't think that they're going to end up in a trash heap someplace," Moore said. "We're not going to just throw them out. But in terms of actually displaying them in the new (Arch) museum, I don't think it would be possible. We just don't have the space and they really don't fit into the story we're trying to tell."