newell.] GALLATIN RIVER, MONTANA 17 
ing figures. At the bridge itself measurements of volume can not well 
be made, as the stream is divided into four channels, being very swift 
under two of these, and obstructed by piles, snags, and sand under the 
others. Above the bridge, however, is a broad, straight course, where 
measurements can be made by means of a boat and cable. Record of 
the heights of the river was kept at this locality from September 3, 
1893, to June 9, 1894, the river being frozen from January 21, 1894, 
until March 10, 1894, at which time the ice disappeared from the river. 
The gage rod was finally washed out, together witli the crib to which 
it was attached, no discharge measurements having been made while 
it was in place. 
On ^November 16, 1894, a new gage was established by Mr. Arthur P. 
Davis under the northeast corner of the Xorthern Pacific bridge above 
mentioned. This gage consisted of timbers partly inclined and partly 
vertical, the lower inclined portion being graduated from 0.G0 feet up 
to 7.10 feet, and the vertical portion from 7 feet up to 12.10 feet. Bench 
mark Xo. 1 is on the head of a bridge spike, in the top of the pile stump 
to which the lower end of the inclined gage is fastened. It is 0.38 
feet below the 2-foot mark on the gage. Bench mark Xo. 2 is the 
head of a bridge spike driven horizontally into the first pier east of 
the river. It is driven into the north end, and is marked "B. M." It 
is 7.32 feet above the 2-foot mark on the gage. The measurements 
were made by means of a cable across the river 100 yards above the 
bridge. 
A discharge measurement, made on ^November 17, when the water 
stood at the height of 1.11 feet on the gage, showed a volume of 772 
second-feet. The width of the stream was 146 feet; the mean depth, 
2.9 feet; the maximum depth, 4.6 feet; the mean velocity, 1.82 feet, and 
the maximum, 2.26 feet. The cross section is excellently adapted to 
measurements of discharge, having a good gravel bottom. A record 
of river height was begun on December 16, 1894, and the river was 
reported as frozen on December 23. 
The above figures give the total outflow from the drainage basin of 
the Gallatin, as the river empties into the Missouri a few miles below. 
The total area drained is approximately 1,620 square miles, including 
the Gallatin Valley and the surrounding mountain slopes. Thus the 
quantity of water discharged at this time represents the amount flowing 
to waste during the fall, and probably during the winter months. For 
comparison with this it ma3 r be noted that at the gaging station on 
the West Gallatin, below the mouth of Spanish Creek, the area drained 
was 850 square miles, and the average flow for Xovember for five years 
preceding was 490 second-feet. 
Bull. 131 2 
