Colorado: Niobrara; Benton.
Niobrara formation 100 200.,
In the foothills there are typical canyons, as along the Platte forks, and in the northern edge of the sand-hills Those of the upper Republican are the largest, those of the Bad Lands are the most peculiar; and the Niobrara tributary system is the most developed.
The upper course of the Niobrara above the Keya Paha is in a narrow gorge.
At Niobrara, in Knox county, a well 656 ft.
Its groups include the Dakota formation, characterized by a very peculiar rusty sandstone, and the Benton, both of which are rather widely accessible and heavy; the Niobrara; the Pierre shales, which apparently underlie about three-quarters of the state in a deep and heavy bed; and, in the extreme west, the Laramie.
There are almost no Cretaceous outcrops except on the streams, especially the Niobrara, Republican and Platte rivers - and in the Bad Lands.
There were in 1900 small reservations for Omahas and Winnebagoes in Thurston county and for the Sioux in Sheridan county, and an agency for the Santees and Poncas near the mouth of the Niobrara; and at Genoa, where the Pawnee agency and reservation had been located, there was in 1908 an Indian school maintained by the United States government with 350 boarding pupils.
In 1908, however, almost all the tribal lands had been distributed in severalty: the Niobrara Reservation (under the Santee government boarding school for the Santee Sioux and the Ponca) had only 1130 .