About one hundred and fifty miles west from the confluence of the Arkansa and Canadian, this red sandstone is discontinued, being succeeded, or perhaps overlaid by an extensive coal formation. The argillaceous sandstone of this formation assumes various characters at different points. The Falls of the Canadian, particularly described in our narrative, are occasioned by a small ridge of fine argillaceous sandstone of a deep green colour, crossing the bed of the river obliquely. The coal beds in this region are of great thickness, and are apparently extensive and numerous. This formation appears, in a great measure, unconnected with the coal strata along the base of the Rocky Mountains, and the sandstone of the two districts are often remarkably dissimilar. Though the strata in both instances are nearly horizontal, the formation at the base of the Rocky Mountains must have an actual elevation greatly surpassing that of the district now under consideration. For these reasons, we have been induced to consider {299} this as belonging to the small group of mountains we have already had frequent occasion to mention, and which have received from Major Long, the name of Ozark mountains. These we shall now proceed to describe, according to the information in our possession. From an inspection of the map annexed to this work, it will be perceived that the course of the Missouri, below the mouth of the Konzas, is considerably inflected to the east, in order to pass round the end of a range of hills, rising in the angle between this river and the Mississippi. This range increases in elevation for some distance to the south-west, its highest point being somewhere near the sources of the White and Osage rivers, the two most considerable streams originating in these mountains. Farther to the south-west, losing a part of its elevation, it is traversed in succession by the Arkansa and Red rivers from the west, and gives origin to the Washita, the Sabine, and some other rivers of inconsiderable magnitude. Our acquaintance with the country between Red river and the Rio del Norte is too imperfect to enable us to trace particularly the continuation of the Ozark mountains, which is believed to extend to that river, and to have some connection with its great southern bend, below the confluence of the Rio Conchos. We will, therefore, at present, confine our attention to that portion north-east of Red river. Though there is no point of great elevation in any part of the range, the whole is truly a mountainous region, and well entitled to a distinctive appellation. Its parallelism in general direction to the Atlantic coast, and the great chain of the Alleghanies, as well as the character and inclination of its component strata, afford unequivocal indication that it belongs to a different system from the great chain of the Rocky Mountains. In several particulars, there is a striking resemblance between this range