One of their most harrowing experiences with a grizzly occurred on May 15, 1805, on the bank of the Missouri River between the Milk and Musselshell rivers. Clark wrote:
Six good hunters of the party fired at a Brown or Yellow Bear Several times before they killed him, & indeed he had like to have defeated the whole party, he pursued them Seperately as they fired on him, and was near Catching Several of them one he pursued into the river, this bear was large & fat would way about 500 wt
Lewis described the climax of the incident:
he pursued two of them seperately so close that they were obliged to throw aside their guns and poucnes and throw themselves into the river altho' the bank was nearly twenty feet perpendicular; so enraged was this animal that he plunged into the river only a few feet behind the second man he had compelled to take refuge in the water, when one of those who still remained on shore shot him through the head and finally killed him.
When they butchered the animal, they found that a total of eight rifle balls had entered its body in different directions.
—Joseph Mussulman, 1999