The Missouri River, the great tributary to the Mississippi, has often been described as one of the most treacherous and aggressive rivers in the universe. It seems to be actuated by a spirit of unrest and a desire for change, so much so that the center of the river bed frequently moves to the right or left so rapidly as to wipe out of existence prosperous farms and homes. Sometimes this erratic procedure threatens the very existence of cities and bridges, and tens of thousands of dollars have been spent from time to time in day and night work to check the aggression of the stream and to compel it to confine itself to its proper limits. The Mississippi proper brings down from the lakes to its junction with the Missouri River clear water, in which the reflection is so vivid, that the verdure on the banks gives it quite a green appearance. The Missouri, on the other hand, is muddy and turbulent, bringing with it even at low water a large quantity of sand and sediment. At high water it brings with it trees and anything else that happens to come within its reach, but at all periods of the year its water is more or less muddy. At the junction of the two rivers the difference in color of the water is very apparent, and, strange to say, there is not a complete intermingling until several miles have been covered by the current. Under ordinary conditions, the western portion of the current is very much darker in shade than the eastern, even twenty miles from what is generally spoken of as the mouth of the Missouri. The Muddy Missouri rises in the Rocky Mountains. It is really formed by the junction of three rivers--the Jefferson, the Gallatin and the Madison. By a strange incongruity, the headwaters of the Missouri are within a mile of those of the Columbia, although the two rivers run in opposite directions, the Columbia entering the Pacific Ocean and the Missouri finding an inlet to the Gulf of Mexico via the Mississippi. At a distance of 441 miles from the extreme point of the navigation of the head branches of the Missouri, are what are denominated as the "Gates of the Rocky Mountains," which present an exceedingly grand and picturesque appearance. For a distance of about six miles the rocks rise perpendicularly from the margin of the river to the height of 1,200 feet. The river itself is compressed to the breadth of 150 yards, and for the first three miles there is but one spot, and that only of a few yards, on which a man can stand between the water and the perpendicular ascent of the mountain.