There have been several _Salines_, or mines (if we may so term them) of pure salt, discovered in different parts of the Prairies. The most northern I have heard of, is [Pg244] fifty or sixty miles west of the Missouri river, and thirty or forty south of the Platte, near a tributary called the Saline; where the Otoes and other Indians procure salt. It is described as resembling the _salinas_ of New Mexico, and the quantity of salt as inexhaustible. South of the Arkansas river and a degree or two further {187} westward, there are several of these salines, which are perhaps still more extensive. I have been favored with some extracts from the journal of Capt. Nathan Boone[152] of the United States' Dragoons, who made an exploring tour through those desolate regions during the summer of 1843. In his journey, between the Canadian and Upper Arkansas, he found efflorescent salt in many places, as well as a superabundance of strongly impregnated salt-water; but, besides these, he visited two considerable salines. Of the first, which he calls the 'Salt Plain,' he remarks, that "the approach was very gratifying, and from the appearance one might expect to find salt in a solid mass, for the whole extent of the plain, of several feet in thickness." This is situated in the forks of the Salt Fork of the Arkansas. The plain is described as being level as a floor, and evidently sometimes overflowed by the streams which border it. Yet the extent of salt, it would seem, did not realize Capt. Boone's anticipations, as he remarks that it was covered "with the slightest possible film of crystallized salt on the surface, enough to make it white." But he explored only a small portion of the plain, which was very extensive. [Pg245]