133 



1. Do the Redtish which spawn in the inlets of the Idaho lakes really come 

 up from the sea, and when do they first arrive ? 



2. During the spawning season the Eedfish are observed to have their fins 

 more or less worn or frayed-out and to have sores upon the body. Are these 

 mutilations received on the spawning grounds, or are they injuries incident to 

 the long and perilous journey from the sea ? 



3. What are the habits of the Kedfish during spawning time? 



4. What becomes of them after done spawning? Do they return to the sea, 

 to the lakes, or do they all die? 



In order to answer as many of these questions as possible, it became at once 

 evident that an extended series of observations at one of the lakes would be 

 necessary. A camp was therefore established at Alturas Lake last summer on 

 July 20, and the observations begun then were carried on continuously until 

 September 24. 



Alturas Lake is situated at an altitude of 7,200 feet, between two immense 

 glacial moraines extending downward from the eastern spurs of the Sawtooth 

 Mountains. It is about two miles long, four-fifths of a mile wide, and has a 

 maximum depth of 158 feet. Its inlet is a small mountain stream about eight 

 miles long, and thirty feet wide at the month. The outlet of Alturas Lake is 

 somewhat larger, and after Howing through Perkins Lake (a small lake about 

 a half mile below) enters Salmon River Valley. After a course of about five 

 miles to the northeast, Alturas outlet joins Salmon River. 



Just above the lake on either side of the inlet tower extremely rugged 

 mountains whose peaks are 9,000 to 11,000 feet above the sea, and the scenery is 

 as wild as any to be found in America. 



In order to study the Redfisli effectually, we set gill nets in the outlet and in 

 the inlet and examined them from day to daj-. The nets in the outlet would tell 

 us wlien tlie fish arrive from below on their way to the spawning grounds. The 

 nets in the inlet wonhl tell us when the fish run up out of the lake to their 

 spawning beds, and also whether they return to the lake after done spawning. 



Witliout going too much into detail, it will suffice to say that daily observa- 

 tions of the lake, outlet and inlet, were made, and the nets, though not kept 

 continuously .set, were so regulated as to assist in solving as many as possible of 

 the problems involved. 



Not a single Redfish was ever caught in any of the nets in the outlet. If they 

 come up from the sea, they had reached Alturas Lake before July 20, when our 

 nets were set. 



