929 GUIDEBOOK OF THE WESTERN UNITED STATES. 
Taken all in all, the Mississippi Valley, in which the train runs 
from Minneapolis to Little Falls, is one of the richest and most 
attractive valleys in the State. 
From Little Falls lead two branch lines of the Northern Pacific, 
one running up the east bank of Mississippi River to Brainerd and 
thence to International Falls, on the northern 
Little Falls. boundary of Minnesota, and the other turning to the 
Elevation 1,134 feet. eft and running to Morris, near the western edge of 
Sc Paul 107 mies, the State. The falls in the river are produced by 
hard slate and schist and by diorite (molten mate- 
rial that was forced up and into the sedimentary rocks and that 
has since been consolidated, forming a hard, dense, dark rock) of 
Archean age. (See table on p. 2.) These rocks are not massive like 
the granite at St. Cloud and so they do not make good building 
material, but they are as hard or harder and form a persistent obstacle 
to the easy flow of the river. The falls are of great commercial 
importance, as they furnish 10,000 horsepower, which is utilized by 
sawmills having a capacity of 70,000,000 board feet of lumber 
annually, flour and paper mills, and an electric-light plant. 
Here once lay the margin of a great evergreen forest that stretched 
wild and unbroken to Duluth and the falls of Sault Ste. Marie, but 
now only a few pine trees can be seen here and there along the railway, 
for most of them have disappeared in the insatiable maws of the 
great lumber mills. Little Falls is noted among archeologists as a 
place where a large number of flint implements, belonging to an early 
race of men, have been found. 
At Little Falls the traveler crosses Mississippi River for the last 
time in his westward trip; he will soon pass out of the Mississippi 
drainage basin and enter another whose waters find an outlet to the 
north. After leaving the river the train passes through a country 
that is typically glacial in all its features. The hard rocks are covered 
by drift varying in thickness from 35 to 400 feet. Owing to this thick 
cover the present surface of the ground gives no indication of what is 
beneath, and for many years it was supposed that this swampy coun- 
try, covered only with brush and scrub oak, was of no value whatever. 
After some of the great deposits of iron ore in Minnesota and Wiscon- 
sin had been exploited it was found that the best way to prospect for 
iron ore in this region was with the magnetic needle. Many parts of 
Minnesota were tested unsuccessfully, but in 1895 it was found that 
the magnetic needle was affected in this area, and drilling has shown 
that it is underlain by a large body of iron ore. This deposit is now 
known as the Cuyuna (ki-you’na) iron range and is one of the three 
important iron ranges of the State. This range (see map of Cuyuna 
