LIMESTONES.-ECONOMIC GEOLOGY.

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rich, and supports in places a heavy growth of timber. The deposit along Rock river is not so rich, and is composed more of sands and clays, with occasional strips of better soil. A number of the bluffs along Rock river are composed in part of loess clays, in which no fluvatile shells were noticed. This formation is of quite limited extent.

The drift proper is very largely developed. It is composed of loose detrital matter, which is often of considerable thickness, brought from long distances, and deposited over large areas of the county. This material is thought to have been brought from the metamorphic regions of the north by the action of water. The railroad track from Beloit to Caledonia cuts at intervals through long, undulating swells of land. These swells are pure, unmodified, unstratified drift. Other railroads exhibit the same beds along their tracks, though in a less marked degree. Every township in the county has these gravel beds, and their underlying associate deposits of clay and sand.

Two-thirds of Winnebago county is underlaid by the Galena limestone. It is a heavy-bedded, yellowish, dolomitic limestone, compact and irregular. There are several notable quarries and outcrops. The first heavy outcrop of the Galena limestone on Rock river in this county is about three miles above Rockford. All the cuts on the Galena division of the Chicago & Northwestern railway, which runs across the southern part of the county, show the lead-bearing rocks. One of the heaviest outcrops is east of Harlem station, on the railroad running from Rockford to Caledonia. The strata are massive and solid, and furnish splendid material for railroad masonry.

The Blue limestone succeeds the Galena in the descending order. It is largely developed in the northern and northwestern portions of the county. It is a thin-bedded, bluish-gray limestone. The first two cuts east of Shirland, made by the Western Union in its excavations for a track, are perhaps the best exposures of the Blue limestone.

Only a limited portion of the county is underlaid by the Buff limestone. The chief outcrop of this formation is at the village of Rockton, where it is forty-five feet in thickness.

The county is not without resources in economic geology. The three formations of the Trenton rocks, previously noted, furnish building stone of good quality. Age does not affect it, and buildings erected sixty years ago are still well preserved. This is especially true of the Galena limestone. The quarries

at Argyle, Rockford and at other points north and south of Harlem supply material for railroad masonry. The Buff also furnishes stone of good quality for ordinary mason-work, and is easily quarried and worked. At present there is only one quarry of the Blue limestone in the city.

Sands and clays for economic purposes are found almost everywhere along the banks of the rivers, and may be obtained from thickly strewn drift deposits. For some years a fine molding sand was obtained north of School street in Rockford, but this supply is now exhausted. About two miles northeast of the city there is a large surface of molding sand, which has been used by all the foundries in Rockford for the past ten years. There is also a quantity of molding sand in the vicinity of Rockton. Lime of excellent quality is obtained in large quantities in and around Rockford. Near Brown's creek there is a bed of white clay; and good red brick is obtained from the clay in other parts of the county.

There is also a supply of good building sand. Limestone for rubble masonry abounds in almost unlimited quantity about Rockford. Large footing stone is obtained, but nothing for ornamental purposes. There is no available sandstone in the county. There is a general uniformity with the geological formation of the Rock river valley. Bog iron exists around many of the springs, but this deposit has no economic value. The ground is impregnated with iron, which is soluble in water, so that it disintegrates lime mortar in the foundations to the extent that it is necessary to use cement in place of lime for foundations. The county possesses very little mineral wealth. The deposits of peat are not of great value. The peat is not available for fuel, and can only be used as a fertilizer. Copper in its pure state has occasionally been found; but there is no deposit of the metal.

The topography of the county may be briefly noted. It is well watered with fine streams. Rock river enters the county about six miles from its northeast corner, at Beloit, runs nearly due south to Rockford, then bends gradually to the west and enters Ogle county. It affords water-power at Beloit, Rockton and Rockford. Pecatonica river enters the county from the west, eight miles from its southwestern corner, and flows in a general easterly and northerly course about twenty miles, and empties its turbid waters into Rock river near the village of Rockton. Sugar river enters the county from the northwest,

and flows into the Pecatonica near the village of Harrison. Other streams are Kishwaukee river, and Killbuck, Kent's, Keith's, and Kinnikinick creeks.

The Indian names of these streams have their significance. Pecatonica means the "crooked stream," or "muddy water." Sinissippi, the Indian name of Rock river, signifies "the rocky river." Kishwaukee means "clear waters." The name Winnebago is translated "fish-eater."

A considerable portion of the county was covered with timber of various qualities. There was much scattering timber and brush-land in the northwestern portion along Sugar river and its tributaries, and on portions of the northern bank of the Pecatonica. This area is interspersed with occasional swampy tracts. In the southern portion of the county, along and near the Kishwaukee creeks, the face of the country is rough, hilly, brushy, and was covered with an occasional growth of timber. A few miles below Rockford, along the northern bank of Rock river, and extending north and west from the same, there is a tract of barrens covered with brushwood, and a light growth of white oak and other timber. The other portions of the county are chiefly prairie, interspersed with small and beautiful groves. For agricultural purposes the county is not considered equal to Stephenson on the west, nor "Little Boone," its eastern neighbor.

CHAPTER III.

THE MOUND-BUILDERS AND THE WINNEBAGO INDIANS.

PROF. J. W. FOSTER, in his Pre-historic Races of the

United States, says: "The subordinate valleys of the Rock river, the Fox, Kankakee and Illinois, show abundant evidence of former occupancy by the Mound-builders, and whilst the mounds are inconspicuous, they are not destitute of relics, and the human remains are indicative of a race whose skulls are marked by peculiarities which distinguish them from the red man."

Three classes of mounds were found in Winnebago county. There was the common round mound, from ten to thirty feet in diameter, and from two and a half to five feet high. These mounds were quite numerous along the banks of the Rock, Kishwaukee and Pecatonica rivers. The oblong-shaped mound is much less common, but is frequently remarkable for its great length. One was found within the present limits of Rockford which measured one hundred and thirty feet in length, twelve feet wide at the base, and three or four feet high. Mounds of the third class have a fancied resemblance to some form of animal life, and are called "effigies." The most common forms of these are called Bird and Turtle mounds, and are found in many localities in the county. Some fine specimens of this class, as well as the round and oblong mounds, are still carefully preserved on the grounds owned by the Misses Beattie and Mrs. Clara G. Sanford, north of the city water-works, on the west side of the river. The round mounds were frequently constructed for the purpose of sepulture, the elongated for circumvallation or as "game-drives," while the effigies were probably ceremonial.

A number of archæologists believe that the builders of these mounds were a race inhabiting this country before the American Indian; and in the absence of any information concerning their origin, they are denominated "mound-builders." Other recent authorities incline to the opinion that the mounds

were constructed by the ancestors of the Indians. Their earth-works are found in large numbers in Rockford and vicinity; there are probably not less than five hundred within the limits of Winnebago county. These earliest inhabitants had no beasts of burden, and naturally their travel and traffic were largely by canoe up and down the rivers. Their settlements, therefore, and their monumental mounds were uniformly located near or upon the river banks; and in the vicinity of the confluence of streams these united evidences of a dense population are generally abundant. Near the mouth of Kishwaukee river more than one hundred have been surveyed by Prof. T. H. Lewis, and probably as many existed near Rockton before their demolition during the progress of railroad construction and other improvements. When the cut was made in East Rockford in grading for the Galena & Chicago Union railroad in 1852, many mounds were destroyed; and gruesome evidence of the sepulchral purpose of some of them was given by the fragments of human skeletons disinterred.

Winnebago county does not figure prominently in Indian history. The Winnebagoes occupied it as a portion of their reservation at one time. The earliest Winnebago traditions relate to their residence at Red Banks, on the eastern shore of Green Bay, in Wisconsin, where they traded with the French. This tribe was first met by the Jesuit fathers near the mouth of Fox river, at the head of Green Bay. Confusion may arise from the fact of two rivers with the same name in the same state. One stream rises in Waukesha county and flows in a general southerly direction and enters the Illinois river at Ottawa. The other rises near the southern boundary of Green Lake county, flows westward to Portage City, thence northward until it expands into Lake Pacawa; after a tortuous course it enters Lake Winnebago, issues from the northern end of this lake, flows northeastward and enters Green Bay. These streams are distinguished respectively as Fox river, and Fox river of Green Bay. The latter is always understood whenever the name is mentioned in connection with the history of this tribe.

The Winnebagoes belonged to the Dacota or Sioux nation. During the era of authentic history they wandered to southern Wisconsin and northern Illinois and Iowa. In 1812 the Winnebagoes of Illinois occupied a section, of which this county formed a part. To the south were the Illinois tribes, and the