If this region were the scene of such conflicts as northern France, one of the great and immediate problems would be the construction of roads— roads which would be serviceable in all sorts of weather, for all sorts of traffic. Fortunately material for the betterment of the roads is at hand. Lime stone underlies most of the region, and limestone, crushed and properly applied, makes excellent road metal.
The scenery along Rock River in Ogle County is similar to that along the Illinois River in La Salle County. In both regions the streams have cut their valleys into St. Peter sandstone, and similar topographic forms have resulted.
Trenches could be made in some of the mantle rock easily and in some of it only with more or less difficulty. Trenches in some sorts of material would drain readily, while in some drainage would need to he provided with much care. Trench walls would stand much better in some sorts of material than in others. Problems involving these elements can be studied to good advantage close to Camp.
'Funneling and mining have been important in some places in the European battle-fields, both in Italy and France. The steep slopes of the Rock below the Kishwaukee afford opportunity for practice in tunneling in rock which is excavated rather easily. Problems in the timbering of tunnels or other excavations also could be I R. D. Salisbury and H. H. Barrows, The Environment of Camp Grant, Bulletin No. 39, State Geological Survey.
The Kishwaukee River Basin occupies that part of the Rock River Basin lying east of Rockford, extending from the state line to DeKalb. The principal cities within this area are Harvard (3,008), Woodstock (4,331), Marengo (1,934), Belvidere (7,253), Sycamore (3,926), and DeKalb (8,102). Woodstock is on the divide between the Rock and the Fox river basins. Belvidere is the county seat of Boone County, and Sycamore of DeKalb County. DeKalb is the seat of the Northern Illinois State Normal School.
Rochelle (2,732) is the largest city in Ogle County, and Oregon, on Rock River, is the county seat.
Dixon (7,216), on Rock River, is the county seat and largest city in Lee County. Amboy (1,749) is located near the center of Lee County.
Sterling (7,467) and Rock Falls (2,657) are located on opposite sides of Rock River in the eastern part of Whiteside County. Water-power has been developed here. Morrison
(2,410) is the county seat of Whiteside County.
Rock Island (24,336), Moline (24,199), and East Moline (2,666) form a compact urban district located on the Missis sippi River just above the mouth of Rock River. With Daven port, Iowa (43,028), on the opposite bank of the Mississippi, this urban district has a popula tion of nearly 100,000. The United States Arsenal is located on an island in the river at this point. Rock Island is the county scat of Rock Island County. Rock Island and Moline manufac ture agricultural imple ments on a large scale. The combined popula tion of Rock Island, Moline, and East Mo line comprises 70 per cent of the population of the county.
A state hospital is located at Watertown (525), a village on the Mississippi just above East Moline.
Cities between Rock and Illinois rivers.—The strip of land along the Mississippi between the mouth of Rock River and the mouth of the Illinois, including about one-half of the length of the state, and extending eastward to the divide between the Mississippi and the Illinois, is a narrow irregular strip varying from about two miles in width in Calhoun County to sixty miles in :Mercer and Henry counties. In Hancock County the divide approaches within eight miles of the Missis sippi. This area contains two cities of considerable size, Quincy and Monmouth, while Galesburg and Galva are situated on the divide. Along this stretch of the Mississippi are found three important cities in Iowa: Burlington (24,324), Fort Madison (8,900), and Keokuk (14,088); also Hannibal (18,341) and Louisiana (4,454) in Missouri.
Aledo (2,144), the county seat, and Keithsburg (1,515), on the Mississippi, are the principal towns in Mercer county. Oquawka (907), the county seat of Henderson County, is a river port.
Monmouth (9,128), the county seat of Warren County, is an important railroad cen ter and manufactures pottery.
Nauvoo (1,020), on the Mississippi in Han cock County, is the largest river port in Illi nois without a railroad. In 1S44, at the height of Mormon prosperity in Illinois, Nauvoo was a city of 16,000 inhabit ants.