In December of 1804, there is some indication of tension between he Mandan Indians and other tribes in the journal of William Clark:
The mandans apprehended danger from the Shar has as they were at peace with the Seaux; and wished to Kill them and the Ricarees (or Panies) but the Cheifs informed the nation ["]it was our wish that they Should not be hurt, and forbid being Killed &c."
When Lewis and Clark came upon the Mandans in October of 1804, the two groups were almost immediately friendly and cooperative. However, as the exploring corps would soon discover, other tribes, such as the Sioux, were nearly as fiercely protective and defensive as the Mandans were welcoming, and all was not necessarily well in relations between the native groups. That autumn, as everyone prepared for winter, Lewis and Clark tried to broker a peace between the Mandans and their immediate enemy, the Arikaras, who, as mentioned above, had more or less allied themselves with the Sioux, at least temporarily. While the Mandans were agreeable, or at least said they were, and both sides participated in the peace process, by December of 1804, the time of the above mentioned journal entry, conflict had begun to flare up again.