From NPR's Day to Day (Feb. 11, 2004):

The journals of Lewis and Clark record that on this day in 1805, the Shoshone woman Sacagawea, who, with her French-Canadian husband, was helping guide the expedition--she gave birth. Officially, the only birth noted by the Corps of Discovery, though some Native Americans have claimed that some of the explorers, including the leaders, fathered other children with tribal women. Historians don't know. But with the Lewis and Clark bicentennial celebrations, people have all sorts of questions. From South Dakota Public Radio, Brian Bull reports.

Unidentified Voice: It is a beautiful evening.

BRIAN BULL reporting:

At the Lewis and Clark Interpretive Center in Sioux City, Iowa, visitors watch robotic figures of Meriwether Lewis and William Clark mourn the loss of companion Sergeant Floyd.

Unidentified Voice: You spend months thinking of everything you can possibly need on an expedition, but somehow you're still unprepared for moments like this.

BULL: But Lewis and Clark were prepared for meeting and consorting with members of the opposite sex. One encounter was recorded by Clark in November, 1805, read here by an actor.

Unidentified Actor: An old woman and wife to a chief of the Chinooks came and made a camp near ours. She brought with her six young squaws, I believe, for the purpose of gratifying the passions of the men in our party. Those people appear to view sensuality as a necessary evil and do not appear to abhor it as a crime in the unmarried state.

Ms. MARCIA PULL (Lewis and Clark Interpretive Center): They were young men, they were full of passion. They had to be full of passion.

BULL: Marcia Pull, assistant director of the center, says while some tourists are shocked upon hearing about the explorers' sex lives, she says it makes for good history.

Ms. PULL: People are much more interesting with all of their, shall we say--I'm not sure--their imperfections, perhaps, is one way of put--but we're all human beings. And I think that tells us more about who these people were....

Professor BRAD TENNANT (Presentation College): If a person had intercourse with a woman, and then that woman would have intercourse with her husband, the power from one person to the next would be transferred to pass on that ability to be good hunters, be good providers. And here you have this new group of people who are seen as being very special, as having big medicine.

BULL: Indians were especially taken with Clark's slave York, whose dark skin and physique suggested very big medicine. One Arikara warrior had York spend a night with his wife and sat outside the lodge to keep the two from being interrupted.

But there were misunderstandings. In November 1804, Sergeant John Ordway's affair with an Indian woman nearly ended in tragedy.

Prof. TENNANT: If the women engaged in sexual relations unbeknownst to their husbands, they could be kicked out of the community, they might even be physically punished. In the case of John Ordway, when the husband returned and found Ordway with the woman, the woman was actually stabbed several times.

BULL: Clark ordered Ordway to give the husband some trinkets, then told the Indian couple to go home and make up. Later, while wintering with a Mandan in 1805, Clark described the buffalo dance used to transfer an elder's skill, say, to hunt, to a younger man through sex with his wife.