12 U. S. BUREAU OF FISHERIES. 
grass, alge, and other water plants in which small crustaceans abound. 
The senior author observed that Straight Creek teemed with brook 
trout of all sizes up to 12 inches long. Hundreds, mostly about 6 or 
7 inches long, were observed. The fish were the most beautifully 
colored seen in the park. Males only 3 or 4 inches long showed the 
brilliant coloration of the fully developed fish in breeding season. 
Females 6 inches in length and upward had well-developed eggs. 
Grizzly Lake contains very large brook trout. 
Above Osprey Falls the Gardiner is a clear, cold stream, having a 
temperature of about 50° F. The bottom is composed of numerous 
stones and bowlders, and there are many deep holes. This previously 
barren stretch of water now contains the introduced eastern brook, 
Loch Leven, brown, and rainbow trouts. About halfway down from 
the falls to the junction with the East Fork Glen Creek joins the river 
on the left side. Glen Creek has been called the West Fork of the Gardi- 
ner. It rises in the Sepulcher Mountain region and flows southeast to 
Swan Lake outlet, thence northeast, joining the Gardiner at the foot 
of the canyon. It is a small stream, only 5 or 6 feet wide and 1 or 2 
deep, which runs mostly through open meadows, with gravelly and 
grassy bottom. Its waters are very cold, about 48° F. in summer. 
Glen Creek has a waterfall some 70 feet high, known as Rustic Falls, 
at the Golden Gate near the base of Bunsen Peak. A small lake in 
the vicinity of Sepulcher Mountain was stocked with eastern brook 
trout in 1912, but the results are as yet uncertain. Below the falls 
the deep canyon is so choked with bowlders and talus that fish can not 
ascend it. 
Swan Lake is a small, roundish pond about a half mile long, with a 
bottom of crumbled lava. While the water near shore is very shal- 
low, the depth at the center seems considerable. The water is clear 
and cold and abounds with insects and crustaceans. 
Eastern brook trout abound in the creek above the falls, but those 
planted in Swan Lake, it is said, seem to have left the lake for the small 
streams, as they have not been found in the lake. Near the junction 
of the Gardiner with the Kast Branch the stream is rough and bowlder- 
strewn, but of a good volume, much like the Gibbon in character. 
The lower course of the Gardiner below the falls is well stocked with 
native redthroat trout and introduced eastern, rainbow, and Loch 
Leven trouts. Indigenous whitefish, suckers, and minnows also occur. 
Below Mammoth Hot Springs the scalding waters of those springs 
discharge through “‘ Hot River” into the Gardiner. It is said that in 
winter native trout are especially abundant at the mouth of the 
stream. 
GIBBON RIVER ABOVE FALLS, GREBE AND RAINBOW LAKES. 
Gibbon River issues from Grebe Lake, which is located in a marshy 
area in the highlands. Grebe Lake is about a mile long and is one of 
the most attractive small lakes in the park. It was stocked with 
redthroat trout in 1912, but the results are not definitely known. 
Approximately a mile ora mile and a half below Grebe Lake is 
another small lake visited by the senior author and Mr. Dinsmore in 
1919. They proposed to name it Rainbow Lake. The lake drains a 
very extensive marshy area whose arms extend far into the hills, 
with greatly meandering, clear, coldstreams. The lake has a gravelly 
