Not absent — mis-tagged
A generic “Sioux Tribe/Nation” tag on this site once held no journal_entry posts, so an earlier essay reported that the Sioux were missing from the record. That was a catalog error. The journals name Sioux traders in June 1804 and spend late September on the Teton (Lakota) confrontation near present Pierre. Separate essays already treat the Teton Sioux and the Yankton Sioux.
The first meeting on the river is ordinary trade. Patrick Gass, 12 June 1804:
we met five periogues loaded with fur and peltry from the Sioux nation of Indians. We remained with the people to whom these periogues belonged all night
The captains hired from that camp a Frenchman who spoke languages upriver. Three months later Clark’s 25–26 September 1804 entries, with matching days from Gass, Ordway, and Whitehouse, record the Teton stop: councils, a detained barge, and a tense release. Those days are the opposite of absence.
Read the Teton and Yankton syntheses for the nation-by-nation record. This page exists so the generic Sioux label no longer advertises a hole that is not in the journals.