a 
DEVILS LAKE, NORTH DAKOTA. 1l 
fully shown by a study of the normal precipitation records, compiled 
by Mr. E. J. Glass, observer, United States Weather Bureau. From 
these it may be noted that in 1905 the rainfall amounted to but 18.5 
inches, and this scanty amount had not been equalled at the close of 
the present investigations in September, 1907, though May, June, and 
July are the months of the greatest rainfall. 
From July 20 to September 10, 1907, comprising seven weeks, the 
level of the lake dropped approximately one-half foot. Observations 
of the fluctuations of level were made from a tide gauge established 
by the Geological Survey in 1883. At the beginning of the period 
mentioned the lake-level reading was 12.3, at the close it was 11.85. 
At the time of the observations at Devils Lake by the Geological 
Survey a permanent bench mark was established in the yard of Cap- 
tain Heerman. This consisted of an iron post 3 inches in diameter, 
with -a copper cap, driven into the ground. On the top of the cap 
was the inscription “ U. S. Geological Survey B. M.” and in the 
center a crosscut, as here represented : 
Elevation above 
sea 
Feet. 
Datum. 
Beside the bench mark a painted wooden tablet reads: “‘ This bench 
mark is 1,439.08 feet above the sea and represents height of lake in 
June, 1883. Zero of gauge 22.90 feet below bench.” 
Observations made by the Bureau of Fisheries party in August, 
1907, disclose the fact that this bench mark was situated 1438 feet from 
the present shore line and the level of the lake was found to be 1,428.6, 
approximately 103 feet below that of 1883. 
The following quotation from the monograph @ on the Glacial Lake 
Agassiz by Warren Upham, pages 594-595, describes the fluctuations 
in level common to lakes of this region: 
Through the past hundred years maximum and minimum stages of the great 
Laurentian lakes have alternated in cycles of about a dozen years, during 
which comparatively scanty average rainfall for several years was followed 
by unusually abundant rainfall. These fluctuations are similar with those just 
noted in the rainfall of North Dakota. Besides such short cycles important 
secular changes of the mean annual precipitation in this State, occupying con- 
siderably longer periods, have caused remarkable changes in the levels of 
numerous lakes which have no outlets. 
Devils Lake thus shows evidence of having attained, about the year 1830, 
a level of 16 feet higher than its low stage in 1889, reaching at or near the 
former date to the line that limits the large and dense timber of its bordering 
7U. 8. Geological Survey Monograph XXY. The Glacial Lake Agassiz by 
Warren Upham. Washington, 1895. 
