EXPLORATIONS IN COLORADO AND UTAH. 
19 
C.— RIO GRANDE BASIN. 
The Eio Grande rises in the Sagnache and Sangre de Oristo Mountains, at the 
head of San Lnis Park. Its headwaters and its various tributaries are clear and cold, 
flowing through grassy mountain pastures, and being well stocked with trout. Of its 
upper tributaries, the following are all noted as trout streams, although the lower 
waters of all are consumed by the irrigating ditches : Saguache, San Luis, Madenha, 
Orestoue, Piedras, Alamosa, La Jara, Conejos, Pinos, U'te, Sangre de Cristo, Triuchara, 
Costilla, Culevra, and Chama. In these streams thousands of trout are destroyed each 
year by the irrigating ditches, especially at the time of their downward migration in 
the fall. It is stated that nine-tenths of the trout in the San Luis Park have, been 
thus destroyed. The streams of the northeastern part of the i)ark (Madenha, Crestone) 
sink into the great sand dunes, the water rising from below as artesian springs, while 
the waters of the Saguache and the San Luis are lost in the alkaline San Luis lakes. 
Collections were made at the following points : 
1. Rio Grande at Del Norte. — The Eio Grande here is a clear, full stream, with 
numerous trout, as well as chubs, minnows, and suckers. Temperature, 59°. The 
best trout fishing is found still higher up, about Wagon Wheel Gap. More trout 
are destroyed in ditches about Del Norte than anywhere else in Colorado. Species 
from Del Norte are marked D. 
2. Rio Grande at Alamosa. — The stream here is quiet, with a bottom of adobe. 
The water is clear and rather cold (62°). In summer the stream is reduced to the seep- 
age of irrigating ditches. In the deeper parts are multitudes of suckers and chubs. 
Species from Alamosa are marked A. 
3. Rio Conejos at McIntyre’s Eanch, about 15 miles south of Alamosa. — The clear 
stream is here 10 to 20 feet wide and 2 inches to 6 feet deep. The bottom is gravelly ; 
the temperature 65°. Species taken here are marked C. 
4. Rio Chama at Chama.— A clear, cold mountain stream, among those in southern 
Colorado best suited for trout. 
5. San Luis Lalces. — Some 20 miles northeast of Alamosa there is a large depression 
in the plain. Into this flow several trout streams, the chief of these being the Sa- 
guache, San Luis, Madenha, and Crestone. The lower parts of this depression are occu- 
pied by the San Luis Lakes, but in ordinary summers none of these streams reach the 
lakes, the water either sinking into the sand or else being used in irrigation. The 
lakes are some six in number, ranging from 50 rods to 1 mile in length, filling one 
after another from the rains and from the soakage of the streams. They are connected 
by a broad ill-defined channel, usually dry, which extends to the Eio Grande, below 
Alamosa. The lakes are all strongly alkaline. The two examined were strongly im- 
pregnated with soda, and without Ashes or any other animals. The uppermost is said 
to be less alkaline, but evidently all are worthless for fishes. 
FISHES OP THE EIO GRANDE. 
1. Pantosteusplebeius (Baird & Girard) D.,G.,A. ; Catostomus guzmanieims Girard; (Pantosteus jar- 
rovii Cope &. Yarrow; not Minomufi jarrovii Coyie). 
Very abundant every where, especially in the deeper jilaces and eddies, reaching a 
length of about a foot. 
This is the species well figured by Cope and Yarrow under the name of Pantosteus 
