To this group of clay bluffs, which line the river for many miles in distance, the voyageurs have very appropriately given the name of the Brickilns; owing to their red appearance, which may be discovered in a clear day at the distance of many leagues.
By the action of water, or other power, the country seems to have been graded away; leaving occasionally a solitary mound or bluff, rising in a conical form to the height of two or three hundred feet, generally pointed or rounded at the top, and in some places grouped together in great numbers the sides of these conical bluff s (which are composed of strata of different coloured clays), are continually washing down by the effect of the rains and melting of the frost; and the superincumbent masses of pumice and basalt are crumbling off, and falling down to their bases; and from thence, in vast quantities, by the force of the gorges of water which are often cutting their channels between themcarried into the river, which is close by.
The upper part of this layer of pumice is of a brilliant red; and when the sun is shining upon it, is as bright and vivid as vermilion. It is porous and open, and its specific gravity but trifling. These curious bluffs must be seen as they are in nature; or else in a painting, where their colours are faithfully given, or they lose their picturesque beauty, which consists in the variety of their vivid tints. The strata of clay are alternating from red to yellow-white-brown and dark blue; and so curiously arranged, as to form the most pleasing and singular effects (Letters and Notes, vol. 1, pp. 6070, pl. 37).
Painted in 1832 on the Missouri River voyage. Catlin's method of recording landscapes on the Upper Missouri remains a puzzle. He mentions a sketchbook in Letters and Notes, and there is an outline of this scene with brief notes in the SI sketchbook, but it was made on the upriver voyage with a reminder to examine the formation on his return. Other passages make it clear that certain paintings were at least begun in the field or on the deck of the steamboat. The small canvases were easy to mount, colors were kept to a minimum, and the artist was a fast worker. Furthermore, the variety of topographical formations and the pattern of colors in this landscape would be difficult to reproduce even from a carefully annotated drawing.
Matthews observes that Catlin had an intuitive understanding of the geology of the area. The Gilcrease version includes more foliage on the domes, but is otherwise identical to the Smithsonian original, which matches plate 37 in Letters and Notes. The scene is repeated in cartoon 248 (unlocated).