His works were not then in operation, but were sufficiently extensive for the manufacture of five hundred bushels of salt per week. Near his house are the _diggings_ so often mentioned in this region as objects of curiosity. These are irregular, but very numerous excavations of little depth, but evidently the result of the united labours of many persons who were possessed of instruments of iron and steel, as no others could have penetrated, and removed the compact rocky soil, of which the points and brows of the hills are composed. These excavations occur frequently {94} in an extent of two or three miles; and from the amount of labour which appears to have been expended on them, it has been thought by some, that several hundred men must have been occupied two or three years in digging them; but this is, doubtless, much overrated. Whoever were the labourers; it is probable their search was for the precious metals, though at present no indications of any metallic ores, except of a little iron, are perceptible about the diggings. Mr. Lockhart had sunk a shaft to the depth of twenty-two feet, but the appearances continued the same as at the surface.[129] After travelling forty miles from Arrow rock, for great part of the way through open plains, where the high grass and weeds rendered their progress difficult and laborious, they pitched their tent, on the evening of July 21st, on a branch of the Le Mine. Here they saw four Mississippi kites. The forks of the tail of this bird are so much elongated as to resemble some fortuitous appendage, for which, at first sight, they are often mistaken. Sandhill cranes, and flocks of prairie hens were also seen, but were so shy as not to be taken without much difficulty. The country about the Le Mine is beautiful and fertile. The unaccustomed eye, in roving over those extensive undulating prairies, is beguiled by the alternation of forests and meadows, arranged with an appearance of order, as if by the labour of men, and seeks in vain to repose upon some cottage or mansion embosomed in the little copses of trees, or in the edge of the forest, which margins the small streams and ravines in the distance. Their provisions being nearly exhausted, the detachment delayed a short time at their encampment on the Le Mine, to replenish their stock by hunting. This camp was near a place called the Grand Pass, a narrow neck of prairie between the timber of the Saline, and that of a small creek discharging directly {95} into the Missouri. Here the Osage trace passes, and a little beyond falls into a waggon-road leading to the Tabeau settlement.[130]