MIGRATIONS IN MONTANA. 155 



from the east. The swarms flying west had reached Helena July 8 to 

 10, and by the 17th or 18th July had nearly reached Deer Lodge, when 

 they began to lay their eggs July 18. They reached Missoula about the 

 8th or 10th of August, when they began to deposit their eggs. In the 

 spring of 1876 the young hatched out, moving in a southerly direction, 

 and by the 20th or 25th of June acquired their wings and went south, 

 remaining in the valley four or five days, and deposited their eggs at the 

 head of the Bitter Eoot Valley about the middle of July. The next year 

 (July 5, 1877) the locusts which hatched from eggs laid the previous 

 summer were observed departing to the southwest. 



South of Helena the flights, as observed at Hamilton and Bozeman and 

 Virginia City, are usually from the east, over the high Belt Mountains 

 which bound the Missouri and Gallatin Rivers on the east. At Bozeman 

 the universal testimony from various persons showed that the main 

 breeding-place of the locusts which afflict the Gallatin Valley is the 

 Yellowstone Valley, which lies due east, though sometimes swarms 

 arrive from the Judith Basin. They fly over the Belt Mountains, and 

 the farms which lie close under the foot-hills do not usually, if ever, suf- 

 fer, as the locusts are borne for a mile or two beyond the base of the 

 mountains before alighting. 



At Bozeman, in 1865-, the locusts came late in the season from the 

 northern and departed in a southwest direction. In 1866 they came 

 both from the Yellowstone and Judith Basins, having been traced thence 

 by emigrants. In 1876, however, instead of departing in a southwest 

 course toward Virginia City, as they usually do, they seemed to join the 

 general movement southeast, in the direction of the border States, i. e., 

 across the plains. Mr. E. M. Goin, of Bozeman, informed us that the 

 locusts which infest Bozeman hatcn in the bad lands of the Yellow- 

 stone, due east of Bozeman, and, when fledged, fly over the Belt 

 Mountains, usually appearing at Bozeman about the 10th of July. lu 

 one summer they flew south from Stirling, and he saw swarms all the 

 way from Stirling to Franklin, Idaho, or, as he expressed it, '' they 

 went ahead of him from Stirling to Franklin.'^ 



At Diamond City the swarms which had come from the east into the 

 Missouri Valley went southwest, and landed in Jefferson Valley, accord- 

 ing to Mr. S. W. Sutherlin. Virginia City, according to Mr. J. H. Ba- 

 ker, is visited by swarms which invariably come from a little north of 

 east. The citizens first hear of them in the Madison and Gallatin Val- 

 leys, and if locusts hatch out in Sun River they are apt to have them 

 at Virginia City. They depart in a course which takes them to Tay- 

 lor's Bridge on the Snake River, a little north of Fort Hall. 



It thus appears that in the arable portions of Central Montana, east 

 of the Rocky Mountain Divide, the main source of locust-swarms is the 

 region of British America lying directly north and east and the Judith 

 and Yellowstone Valleys, separated from the Gallatin, Jefferson, and 

 Upper Missouri Valleys by the Belt Mountains. In years of unusual 



