12 ^yisconsin Academy of Sciences^ Arts, and Letters, 



nois, in the northwestern corner of the state, forms a portion of 

 the Upper Mississippi lead region, which occupies an extensive 

 area in the three states of Wisconsin, Illinois and Iowa, where 

 they corner with each other. The whole area over which lead 

 has been raised, in sufficient quantity to be worthy of notice, is 

 about 4.000 square miles, of which nearly two-thirds is in the 

 state of Wisconsin and the other third about equally divided be- 

 tween Illinois and Iowa. The most productive jDortion of the 

 region, however, is that which lies between Dubuque, Galena 

 and Shullsburg, so that both Iowa and Illinois raise more lead, 

 in proportion to the area over which mining operations have 

 been extended, than Wisconsin does. It is quite impossible to 

 give the exact amount for each state, as the imaginary line which 

 separates Illinois from Wisconsin has no influence in the di- 

 vision of property or the supplies of ore furnished to smelting 

 works. Some of the heaviest deposits of ore in Wisconsin are 

 owned and managed by citizens of Illinois. 



^^The lead bearing district of Illinois is entirely comprised 

 within the limits of Jo Daviess and Stephenson Counties, and 

 by far the larger portion is in the first named county. Indeed, 

 although ore has been found and mined, to some extent, in 

 Stephenson County, and although the proper lead bearing rock 

 covers a large area in that county, yet we are not aware of any 

 diggings now in operation outside of Jo Daviess County. In 

 fact, a circle of four miles radius, with its center a little north- 

 east of Galena, would include nearly all the productive diggings, 

 with the exception of those at Apple River and in the vicinity of 

 Elizabeth ; and certainly nine-tenths of the ore raised in Illinois 

 comes from the area included within that circle of only eight 

 miles in diameter."^ 



Map 1, Plate XXI., a reduced copy of one accompanying Pro- 

 fessor Whitney's report, shovrs the distribution of the geological 

 formations found in Jo Daviess County, and also the location of 

 all the lead mines that have been successfully worked. The 

 area on the map unmarked, is non-lead-bearing rock ; in it lead 

 has never been found in paying quantities. The land is valu- 

 able only for farming and stock-raising purposes. The area 



* ■ I.. ^ ■■— ■ I.I.I. III. — .. . 11. — ■ — ^-.i — .■■■ — -. ■.■^— ..— -— — 111.^-. ■ III ■■■■» 



1 Geological Survey of Illinois, Vol. I., p. 155. 



