The Niobrara river drains about 450 square miles of the county on the south and the White river drains all the remainder, except about 35 square miles in the northwest corner, which drains north into the Cheyenne river. The White river rises in Sioux county, about 30 miles west of the Dawes county line, and flows in a northeasterly direction, crossing into South Dakota about two miles from the eastern county line. The valley is approximately 45 miles long, but the length of the stream is much greater because of its meandering course.

Numerous tributaries flow southeasterly into the White river, the most important of which are Big Cottonwood, Little Cottonwood, Rush, and Lone Tree creeks. These streams have carved out narrow valleys and in general are bordered by narrow strips of bottom land. They are cutting rapidly near their sources, and much slower in their lower courses ; but the White river and its tributaries are eroding to a greater or less extent all along their •courses. Numerous tributaries, of which the most important are Beaver, Bordeaux, Chadron. Dead Horse. Indian and Ash creeks, enter the White river from the south, flowing almost due north from their sources in the Pine Ridge watershed. Here they have deep channels, which are being rapidly intrenched.

How County Was Formed

Dawes county was formed from a part of Sioux' county in 1885. Settlement had begun a few years before, and by 1886 nearly all the land had been filed upon under the public- land laws. The lowlands along the White river and Bordeaux creek were first taken up and later settlement spread over the entire county. The early settlers were of many nationalities, a large percentage being American born.