The Missouri River. — Broadhcad. l-')! 
Jeff«r8on Kiver 3,778.3:5 cubit; foot i)er srcoiul. 
MadiHon " 2,670 
Gallatin " 2,n73..33 
Total ..N 8,52 i.G() feet per second. 
The area of the Mis.souri drainage, above the mouth of the 
Yellowstone is 9.'^,0(X) square miles. 
That of the Yellowstone is 78,700 square miles, and both 
united 172,00(J square miles. The entire river drains r)l(),0(X) 
square miles. The mouth of the Yellowstone is 2,{X)0 miles 
above the mouth of the Missouri. 
A striking feature of the Missouri river is its remarkable 
impetuosity for so great a distance ; also the continual whirl- 
ing agitation of its waters, and the large amount of earthy 
material held in suspension. Its character seems different 
from other streams, and it imparts its own character to the 
Mississippi river below their junction. Its range of surface 
below Sioux City (781 miles from the mouth) varies from 16 
to 20 feet. The amount of water discharged is subject to var- 
iation. The observations of Col. C. R. Suter, at St. Charles, 
in 1879, showed a variation from 26,440 to 298,537 cubic feet 
per second for a range of 17-J feet on the gauge, or a low-water 
volume of 1-11 that of high water, and an ordinary range of 
gauge would give volumes of 15,000 and 430,000 per second 
for low and high water, or low water volume 1-28 of high wa- 
ter volume. At Sioux City the variation is about the same. 
The main valley consists of a great rock trough H to 17 
miles wide. From Sioux City down, the bed at one time seems 
to have been filled with glacial drift, subsequently in part 
cleaned out. Boulders are found resting on the bed rock, 
sometimes cemented together with gravel and sand. These 
were found in excavating bridge foundations l)oth at St. 
Charles and at St. Joseph. Below St. Joseph the valley aver- 
ages 2.^ miles in width; above to Sioux City itis wider. 
The general depth to the rock-bed of the lower river, varies 
from 70 to over 100 feet. Most bridge piers have reached solid 
rock. The velocity at St. Joseph at ordinary spring Hoods is 
3 8-10 miles per hour, at low water 2 0-10. At low water the 
channel at St. Josepli is 400 to 500 feet wide and 15 to GO feet 
ileei),and the difference l)et\veen high and low water is 23 feet; 
width at floods 1,420 feet. Rock is 43 to 48 feet bi'low low wa- 
ter. There is a dej)osit of 40 feet resting on solid rock consist- 
