210 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



spring aiid early summer the temperature is so reduced, even in its hottest part, as 

 to make it possible for fish to pass. 



On the 14th we unloaded our boat for a few hours' work on Mary Lake, a clear 

 and pretty sheet of water lying near the summit of Mary Hill, at an elevation of 

 8,200 feet, and we thoroughly examined also the upper waters of Nez Perc6 Creek 

 as we passed down the stream to the Lower Geyser Basin. The 15th we spent in 

 collecting from the lower part of Nez Perce Creek and from the Magpie, its principal 

 affluent, for a short distance above its month. Every condition was found suitable in 

 these streams for the maintenance of fish, and a report to the Commissioner from the 

 field to this effect was followed by a consignment of Von Behr trout, set free in the 

 Nez Perce by Mr. Lucas, of the Commission. 



August 16 was spent on the Firehole Eiver, from the mouth of the Nez Perce" to 

 the junction of the Firehole and the Gibbon, and the 18th on the same stream above 

 the Lower Geyser Basin, our collections ranging from the ford above Old Faithful to 

 the Middle Geyser Basin below the Excelsior Geyser. Excellent opportunities were 

 given here for a study of the effects of the geyser outflow on the animal life of the 

 stream. Some hauls along shore with the surface net were made, in passing, from 

 Goose Lake, near the lower basin. 



On the 17th we collected at Canon Creek again, and from the Gibbon Eiver, at 

 the mouth of this creek, and also above and below the falls of the Gibbon, well 

 known as an impassable barrier to the movement of fishes up this stream. In our 

 collections above and below falls in these rivers and creeks, it was my object to learn 

 whether any other animal inhabitants of these streams were similarly excluded from 

 their upper waters. 



On the 20th we made a trip from Norris Geyser Basin to the Twin Lakes (in one of 

 which whitefish had already been planted by a Fish Commission party), returning by 

 a small lakelet without outlet, called the Lake of the Woods. We went thence to the 

 Grand Canon, collecting by the way from the Gibbon above Virginia Cascade, and 

 from minor waters passed, and on the 22d made a trip to a lake nameless to the guides, 

 but marked Grebe Lake by the geologists, and mapped as the source of the Gibbon. 

 We carried boat, dredge, small seines, and our lighter collecting apparatus to this 

 lake, and thoroughly overhauled it, as typical of its kind. 



Returning to Yellowstone Lake on the 23d, we explored Pelican Creek on the 24th 

 for several miles above its mouth, and on the 25th dredged from two rowboats at a 

 depth of 195 feet, with a bottom temperature of 42.5. Returning next day to the 

 canon, we collected from the lower course of Alum Creek, the upper part having been 

 explored by us previously. On the 27th, sending the wagon to Mammoth Hot Springs 

 by the traveled road, Prof. Lin ton and I took the trail down the river to Yancey's 

 Ranch, crossing Mount Washburn, and making considerable collections from Tower 

 Creek above the fall. On the 28th we went from Yancey's to the springs, stopping 

 by the way at Lava Creek and Blacktail Deer Creek. On the 29th the usual col- 

 lections were made from the Madison, at the crossing of the Cooke City road, and 

 also from Swan Lake on the plateau of the same name, to which our boat and the 

 usual collecting equipment were transported for us by Capt. Boutelle, U. S. A., acting 

 superintendent of the Park. 



