How does Bridger describe the spot where the Mississippi River meets the Missouri River in the biography, Jim Bridger, Mountain Man?

Bridger describes the Mississippi River as placid and green-colored, whereas the Missouri River was a muddy, chocolate color. The water where the two rivers meet was described as oddly clear and the two joined for a time flowing side by side. Then it was off into the Missouri River which was much more violent than the Mississippi River.