138 GUIDEBOOK OF THE WESTERN UNITED STATES. 
Arlee is one of the towns that have begun to grow since the reser- 
vation was thrown open to white settlers. It lies in 
Arlee. a broad valley containing rich agricultural land and 
Elevation 3,094 feet. will doubtless in time become an important farm- 
St. Paul 1,276 miles. ek : ; 
ing center. A familiar scene in this valley is shown 
in Plate XIX, A (p. 119). 
Just below Arlee faint beach lines can be seen on the right (east) 
near the base of the hill, and a short distance farther on a terrace of 
fine light-colored sediment is prominent on the same side of the road. 
This terrace can be followed with the eye as far as the canyon by 
which the river escapes from the valley. It is composed of brownish 
clay and sand and is supposed by some to be the sediment deposited 
at the bottom of Lake Missoula, or it may have been deposited by the 
present Stream when it was ponded by a greater volume of water 
flowing down Flathead River from the melting glaciers to the north. 
The broad valley in which the railway is situated is surrounded on 
all sides by rocky walls, through one of which the stream draining the 
valley has cut a deep gorge. Such a basin is seldom, if ever, produced 
in the normal development of a stream, but is common in the moun- 
tainous part of Montana. It is Supposed to have been formed by 
the depression of the bottom of the basin, thus leaving the walls 
standing high above the valley floor. — 
The rocks exposed in the walls of the canyon belong to the Belt 
series and consist largely of quartzite and argillite. In many pro- 
tected places in the canyon the white sand and clay deposited by the 
flooded Flathead River can be seen, showing that this body of water 
filled not only the valleys where they are wide, but also the narrow 
canyons connecting them. 
At Ravalli the valley is narrow, but the hills are smooth and com- 
paratively low. A stage line runs from this place north 30 miles to 
Polson, at the lower end of Flathead Lake, where 
aa oe connection is made with boats for Kalispell and other 
St. Paul 1286 mites, Wns on the Great Northern Railway. Ravalli is the 
distributing point for a large part of the Flathead 
Reservation. Much of the best land for agriculture lies across the 
\Ttis ible to account for the forma- i a Pre, 
tion of ie herta in this manner, but how <sRgi —— ate pagaerg aette 
formation was so slow that the stream cut | which the basin had been filled. Which 
the rock faster than it was uplifted. | of these explanations fits the case in hand 
(2) The basin was formed so rapidly that | can not be told without a detailed study 
the water was ponded forming a lake. i 
] certain marks, if it has occ ‘ 
the rim, and the stream thus formed cut | and it is through the study of these char- 
acteristic marks that the question can be 
answered. 
