A large party of Ehanktonwanna and Teetonwan Dakotas, says the legend, had gathered together at the quarry to dig the stone. Upon a sultry evening, just before sunset, the heavens suddenly became overclouded by a heavy rumbling thunder and every sign of an approaching storm, such as frequently arises on the prairie without much warning. Each one hurried to his lodge, expecting a storm, when a vivid flash of lightning, followed immediately by a crashing peal of thunder, broke over them, and, looking towards the huge bowlder beyond their camp, they saw a pillar or column of smoke standing upon it, which moved to and fro, and gradually settled down into the outline of a huge giant, seated upon the bowlder, with one long arm extended to heaven and the other pointing down to his feet. Peal after peal of thunder, and flashes of lightning in quick succession followed, and this figure then suddenly disappeared. The next morning the Sioux went to this bowlder and found these figures and images upon it, where before there had been nothing, and ever since that the place has been regarded as wakan or sacred. Mr. T. H. Lewis (_b_) gives a description of Fig. 51. [Illustration: FIG. 51.--Petroglyphs in Brown’s valley, Minnesota.] This bowlder is in the edge of the public park, on the north end of the plateau at Brown’s valley, Minnesota. The bowlder has a flat surface with a western exposure, is irregular in outline, and is about 5 feet 8 inches in diameter, and firmly imbedded in the terrace. The central figure, _a_, undoubtedly represents a man, although the form is somewhat conventional; _b_ represents a bird; _c_ represents a tortoise; _d_ is a cross and circle combined, but the circle has a groove extending from it; _e_, _f_, and _g_, although somewhat in the shape of crosses, probably represent bird tracks; _h_ and _i_ are nondescript in character, although there must be some meaning attached to them; _k_ and _l_ are small dots or cups cut into the bowlder. The figures as illustrated are one-eighth of their natural size, and are also correct in their relative positions one to the other. The work is neatly done although the depth of the incisions is very slight. MONTANA. Mr. Charles Hallock, of Washington, D. C., reports the occurrence of pictured rocks near Fort Assiniboin, Montana, but does not mention whether they are colored or incised, and also fails to describe the general type of the characters found. NEBRASKA. The following (condensed) description of petroglyphs found in Dakota county, Nebraska, is furnished by Mr. J. H. Quick, of Sioux City, Iowa: