SUMMER BIRDS OF FLATHEAD LAKE. 293 



Further Notes on the Summer Birds of Flathead Lake. 



The following notes are based upon observations made from May 30 

 to July 30, 1902. The first three weeks of June were spent at the head 

 of Swan lake; the remainder of the time was given to observation in the 

 immediate vicinity of the Biological Station. As a supplement to the 

 notes made during the seasons of 1900 and 1901, which were reported in 

 the bulletin entitled "The Summer Birds of Flathead Lake," issued under 

 the direction of the University of Montana Biological Station, these further 

 notes are deemed worthy of publication. Several important species, 

 overlooked in the previous seasons, were noted in 1902; and as a com- 

 plete record of our observations for the region is desirable, the notes 

 herein given will serve to fill out somewhat that which was lacking in the 

 larger bulletin. As previously stated, no attempt has been made to fur- 

 nish a complete list of the birds of the Flathead region, but simply to 

 report such observations as were made by our party during the collecting 

 season; hence no authorities have been cited. It is merely intended to 

 furnish a record of personal work that may be helpful to other observers. 



SWAN LAKE. 



Among the many little lakes which lend interest and beauty to tne 

 Mission, Swan, and other ranges of our Montana mountains, Swan lake 

 is worthy of consideration because of many delightful features. It is an 

 expansion of Swan river, or the Big Fork, the outlet of the lake into 

 the river being about eight miles overland from the Biological Station, 

 in a direction somewhat south of east. A very poor road, generally over- 

 flowed during the time of high water in the spring, but tolerably passable 

 at other times, leads from the Station to the foot of the lake. Another 

 road, generally in ordinary condition, follows a course around the bend 

 of Swan river to the northward, thus furnishing access to the lake at 

 all times, the distance over this road being about fifteen miles. 



In its origin the lake bed is probably the result of glacial action, 

 whereby in remote ages an irregular furrow was ploughed by the moving 

 ice-mass. The situation is between the northern end of the Mission 

 range and the southern end of the Swan range, and nearly parallel to the 

 eastern shore of Flathead lake. From the tops of the Mission summits 

 between the two lakes, both can be easily seen, the separating crests 

 being not more than five or six miles in breadth. 



Swan lake is said to be about twelve miles in length, and the average 

 width is at least half a mile. The contour of the lake is formed by 

 several successive slightly cresentic bays or enlargements. At its 

 head it opens out into a nearly circular area about two miles in diameter, 

 above which lies a large submerged region in the spring, though later it 



