FISH FAUNA OF LAKES OF SOUTHEASTERN OREGON, 73 
north, however, it soon becomes apparent that what before appeared as a flat- 
topped mountain is really a great wall which rises some 1,800 feet above the floor 
of the basin, and with only slightly varying height extends almost to the northern 
boundary. South of the transverse ridge the basin is bordered by bluffs and ranges 
of hills which gradually rise perhaps a thousand feet as they recede from the valley. 
Swinging round to the westward the bordering heights assume greater proportions 
and are more abrupt. North of Honey Creek they become broken, falling away 
into rounded hills and low plateaus. In the northern part of the basin a definite 
and well-preserved shore line extends along nearly the entire face of the eastern 
escarpment. It appears to be somewhat over 300 feet above the floor of the valley. 
Abert Lake occupies part of a basin which is somewhat similar to that of 
Warner Lake, bordered by a high, precipitous wall on the east and low bluffs and 
rolling hills on the west. It is about 15 miles long and nearly a third as wide. The 
water of the lake, said to be not over 18 feet deep, is muddy and intensely alkaline, 
nothing growing near it.? It is fed almost entirely by the Chewaucan River, which 
drains the northeastern part of the Winter Mountains, where they are covered with 
forests, especially on the slopes exposed to the south and west. Deep snow lying 
late in the season and an abundance of rain give the river a large volume of clear, 
cold water. After emerging from the mountains it flows, a deep, sluggish stream, 
across the great Chewaucan Marsh and finally passes over a fall into the lake. 
At the north end of Abert Lake, on the XL Ranch, is a remarkable spring. Its 
water has a temperature of 61° F., is said to be constant in volume, clear, and fresh. 
It pours at once into a boggy pool 100 feet in diameter and about 17 feet deep, from 
whence an outflowing stream spreads over a marsh of tules and rushes. The water 
of the pool is clouded with algw and swarms with fishes (Rutilus). “A handful of 
crumbs thrown out on the surface attracts great numbers, causing the water fairly 
to boil, the food disappearing almost instantly. One haul of a seine net inclosed 
hundreds of specimens measuring from a few inches to nearly a foot in length. 
Their stomachs were stuffed with vegetation and numbers of a minute gasteropod. 
Whether the fishes derive their entire support from the pool was not learned. A 
few were seen in the stream leading from the pool, and it is reported that during wet 
weather great numbers pass out to the marsh, where they are left to die as the dry 
season approaches. The fishes are no doubt natives of the spring, the species having 
been left by the retreat of the desiccating lake. 
Summer Lake is somewhat smaller than Abert. It is muddy, alkaline, and 
very shallow, the greatest depth not exceeding 15 feet, and much of that is soft mud. 
The bottom slopes very gently from the shore, avocets being able to wade out over a 
hundred feet. Consequently a slight reduction in the volume of water contracts 
the area of the lake considerably. It has maintained its present level for at least 
forty years, as stated by residents of the valley, the shore line occasionally retreating, 
however, during dry seasons as much as 150 yards. Sometimes a strong wind will 
drive the water back 200 yards or more, when a long reef of the stumps and fallen 
aCope (Proceedings Academy Natural Sciences Philadelphia, 1883, p. 138) says: ‘‘It abounds in fishes, especially the 
trout Salmo purpuratus.” Residents of the region report that fishes may often be found in the lake at the mouth of the 
Chewaucan River, where many, having passed over the fall, die from contact with the alkaline water. 
