The bears chased members of the Corps through the woods, into bushes, into the water. On July 15, 1806, Hugh McNeal was out alone on horseback. All of a sudden he saw a grizzly bear in the bushes. His horse bucked and threw McNeal near the bear. The bear raised itself up to attack. What could McNeal do at such close range? He hit the bear with his gun. The bear was temporarily stunned and fell down. McNeal quickly climbed up a nearby tree. Because of their large size and straight claws, grizzly bears aren't good tree climbers, so the bear waited at the base of the tree. And waited. And waited. Finally just before dark, the bear gave up and left. McNeal climbed down and got back to camp safely.

By the end of the expedition Lewis believed that the Corps had been very lucky to not lose anyone to a grizzly bear. He wrote that "the hand of providence has been most wonderfully in our favor."