Page:History of Iowa From the Earliest Times to the Beginning of the Twentieth Century Volume 1.djvu/48



broken land, cut up into steep hills, generally extend back from the water courses, through which deep ravines have been cut in all directions. This land is generally covered to some extent with growth of stunted oak and hickory trees, among which are thickets of wild plum, crab apple and hazel bushes. These lands were called “barrens” by the early settlers. The soil of this hill land is productive, producing grain, grass and fruit of excellent quality. The “Missouri Slope” is the name given to that portion of Iowa which is drained into the Missouri River. The soil is a bluff deposit, generally destitute of surface stone and gravel, or rock strata beneath, and produces excellent crops of grain, grass, vegetables and fruit. The bluffs along the Mississippi River rise to a height of from one to two hundred feet, everywhere intersected with deep ravines. They are generally treeless, but in some places small timber is found. Northern Iowa is but gently rolling fifty miles west of the Mississippi, while the southern half of the state is more broken into hills and valleys, and has large tracts of woodland.

Although essentially a prairie state, almost every variety of surface soil is found, showing conclusively that it is not the peculiar soil formation which causes forests to grow in one locality and prairies to be found intermingled with them.

After more than half a century of investigation of the causes which have produced the prairies, the problem is yet unsettled. No theory yet advanced explain satisfactorily why the treeless plains begin in certain sections of Michigan, Indiana, Wisconsin, Missouri, Kansas and Louisiana, without any noticeable difference in soil or surface. In many places in the states where the prairies predominate, remains of forests are found that show evidences of having existed for hundreds of years, and among the mare prairies which furnish no indications of ever having been covered with trees.

The origin of the prairies is one of the most interesting