"Capt. Lewis, have you ever heard of yogurt?"

Yogurt probably wasn't a Clatsop Indian staple two centuries ago, but the interpreters portraying members of the Corps of Discovery at Lewis and Clark National Historical Park-Fort Clatsop made a few concessions to 21st-century tastes as they traded with the "natives" visiting their rough encampment.

But the re-enactors otherwise stayed true to character in the roles of Lewis and Clark's party at the park's Bicentennial program, which continues through Tuesday.

The group of Living History interpreters, the largest the park has hosted, was supposed to take over the replica fort for its weekend-long program. With the structure destroyed by fire just five weeks before the Bicentennial, organizers quickly altered the program. They moved the encampment a few yards away along the new shuttle stop trail and had the interpreters set to work on the same tasks the Corps members were busy with when they first arrived at the site in early December 1805 - erecting tents, chopping firewood, stripping trees for tipi poles and making plans for the fort they would build.

Visitors were briefed on the Living History program during the shuttle ride from the Netul Landing parking area to the park. They were invited to interact with the re-enactors, but warned the party would know nothing about cell phones, cameras or anything else from the past two centuries.

"This is fascinating, I should have such a device," "Capt. Lewis," aka David Scott, said to one of the men as he admired one visitor's umbrella.

Chewing gum offered by another visitor was equally mysterious - Astoria schoolteacher Tom Wilson, portraying Sgt. John Ordway, asked what tree it came from, and after sampling some said it was completely unlike the pine pitch the men sometimes chewed, but agreed to make a trade for it anyway.

Trading, just like the original explorers did with the local Clatsop Indians for badly needed supplies, was encouraged, and Boy Scout Pack 294 from Scappoose came prepared for some serious bartering. Members of the group, who had studied the explorers en route to earning a special Lewis and Clark patch, brought a variety of items, including needles, beef jerky, a tin of flour and some potatoes, standing in for wapato root, that the real Corps would have desired.

"This is exactly what our men need," Ordway told Robert Ohling, giving him a copper wire with a bell attached in exchange for the flour.

George Saenz of Manhattan Beach, Calif., got two small bells and a mirror for some dried dog meat - three beef sticks. A Lewis and Clark fan for 30 years, he found the re-enactors' performance excellent, but had a question for Lewis - when would they compensate the Clatsops for all the trees his men cut down?

Ted Kaye, former executive director of the state Bicentennial organizing group, offered the members a Sacagawea dollar coin. They were puzzled that the young girl they knew as "Janie" or "Mrs. Charbonneau" would grace a golden coin, but accepted the gift, and said they would share it with her.

"They're doing an excellent job staying in character," Kaye said of the re-enactors. "When these kids go home, they'll say "I met Capt. Lewis."

Walt Walker, who portrays Sgt. Patrick Gass, came with two other members of the Lewis and Clark Honor Guard from Great Falls, Mont. They joined members of the Discovery Expedition of St. Charles, Mo., and Fort Clatsop's own interpreters for the program, his first at Fort Clatsop.

"It's fun to tell the story in a little different situation," he said. "My group concentrates around Great Falls and (Lewis and Clark's) Portage - we're pleased to work with these men, they have a whole new perspective on the expedition."

Walker became involved in first-person historical re-enactments in the early 1990s, driven by a love of history and his own roots, which reach back to the same Virginia county where William Clark's wife was born. He prefers to stay in the background, cutting wood and handling other tasks, but is happy to talk with visitors, even those who try to stump him with questions about obscure facts.

He and other Living History re-enactors put countless hours of research into their roles, but they're aware they can't really know what their characters experienced, he said.

"None of us can absolutely answer any question you could come up with about the expedition," he said.

When Luci Chiotti told "Ordway" she knew how the men were woefully short of clothing when they arrived at the Pacific, that prompted the sergeant to warn one of the other men to "keep a watch on our personal items - some people seem to be reading our journals."

Chiotti, of Portland, her husband Vince and Leilani Olsen came to the Bicentennial to attend today's dedication of the Fort to Sea Trail - Vince worked on the project as part of the state Community Solutions Team - but they found the Fort Clatsop program "one of the best" of the weekend's offerings.

Visitors' questions included how to start a fire and what dog tasted like. But the re-enactors were also able to delve deeper into their characters, as Wilson's Sgt. Ordway did remembering Lewis' reaction when the men reached the Continental Divide, only to see more rugged mountains in their path.

"To see the look on his face - he told us 'we'll proceed on,' but I could see the disappointment," he said.