52 BULLETIN 1017, U. S. DEPARTMENT OF AGRICULTURE. 



Only two of the spring rises have resulted in serious floods through- 

 out the entire valley ; these occurred in April, 1882, and April, 1897, 

 the latter being the maximum for which reliable records are avail- 

 able. The floods of 1893 and 1904 were more serious between Grand 

 Forks and the international boundary than in other parts of the 

 valley. The 1916 flood was most serious in the vicinity of Fargo 

 and in upper portions of the valley, but it was of slight consequence 

 at and below Grand Forks. 



With regard to floods along the part of the river within the 

 United States, records prior to 1880 are vague because no systematic- 

 method for recording gauge heights had been in use before that time. 

 Information as to floods prior to 1860 is merely legendary. Ac- 

 cording to legend a flood occurred in 1852 which was from 1 to 10 

 feet higher than the 1882 flood at and below Grand Forks. Reliable 

 records of floods since 1826 at Winnipeg. Manitoba, are available. 

 The extreme floods there occur in May, nearly a month later than at 

 Grand Forks, and are caused by fortuitous occurrence of high stages 

 in the Red River and the Assiniboine River, which joins the Red 

 within the city of Winnipeg. The maximum flood recorded at Win- 

 nipeg crested May 22, 1826, about 15 feet above the ordinary flood 

 height in that locality. A flood \\ feet lower crested May 22, 

 1852, and stages about 4 feet lower than that of 1826 are said to have 

 occurred in 1776, 1790, and 1809. The highest flood since 1852 oc- 

 curred in 1882 when the crest was 11 feet lower than in 1826. The 

 crest of the flood of 1882 in the Red River passed Winnipeg several 

 days before that of the Assiniboine reached the junction of the 

 streams ; thus a greater flood was averted. Considering these records 

 for the lower river it appears probable that in 1852 a flood higher 

 by one or more feet than that of 1882 occurred along the river at and 

 below Grand Forks. 



The records indicate that a serious flood may occur in any year: 

 that the probable frequency- is once in 15 years; and that the probable 

 longest period without a flood is 30 years. 



THE LAKE TRAVERSE— BOIS DE SIOUX— RED RIVER CHANNEL. 



The Red River of the North is formed at Breckenridge. Minn., by 

 the junction of the Bois cle Sioux and Otter Tail Rivers, and follows 

 a sinuous course to the north for about 394 miles to the international 

 boundary ; thence it continues to Lake Winnipeg. The Bois de Sioux 

 .River rises in Lake Traverse, the total length of the combined water- 

 course from the upper end of Lake Traverse to the Canadian line 

 being 456 miles, which is approximately twice the distance between 

 the two points as measured in a straight line. (See fig. 1.) The stream 

 flows northward through the center of the bed of the ancient glacial 

 Lake Agassiz, the land on both sides being very flat for some dis- 



