[ 237 ] 46 



eration of preserving an absolute neutrality. For, in case of meeting with 

 any hostile parties, an attack might be commenced, the baggage robbed, 

 and the horses stolen, before having time to reconcile matters by a friendly 

 intercourse. 



Early ilie next morning, having distributed our presents to the Yank- 

 Oiuhu-oiu ^^'^^' ^^^ continued our descent of the Coteau du Missouri along 

 or Oakwoo'i the Wamdush/.'a, or Snake river, that takes its rise on the pla- 

 seuiemeui. leau which \ve had just left, to empty itself into the Tchan-san- 

 san. Thence we proceeded to lake Tchan-ra-ra-chedan ^ or lake of the 

 "scattered small wood,"' the aspect of which is grateful to the traveller, 

 but, from the impurity of its water, affords him but little relief; and then, 

 fifteen to eighteen miles farther, we reached the river Jacques, at a very cel- 

 ebrated spot, called by the Sioux Otiihu oju — meaning, literally, the place 

 "where the oaks spring up," but which 1 have designated on my map as 

 the "Oakwood Settlement," 



Otuliu oju (or, as the French call it, Talle de Chtnes) was the place of 

 rendezvous vvuich I had assigned to the reinforcement that was to meet 

 me from Lac qui-parle. It had been for the Sth to the 12th of .luly, and 

 we reached it on the 10th — with laudable exhilaration, it may be believed, 

 after one year's appointment, made in defiance of all unforeseeable acci- 

 dents. The estimate which I have made of the distance between this place 

 and Fort Pierre is about 110 miles; its actual elevation above the sea is 

 about 1,340 feet, and the descent from the Coteau du Missouri to the river 

 Jacques not less than 750 feet. The last 50 miles, by our route, belong to 

 the east slope of the Coteau du Missouri ; but, as we were obliged to st;!:?ct 

 our ground, allowing for this, the whole direct distance is probably 40 miles. 

 In a similar way, estimating the distance to the head of the Coteau des 

 Prairies, which is 30 miles to the east : the basin of the river Jacques be- 

 tween the two coteaux, and in the latitude of Otuhu ojif, may be laid down 

 as having a breadth of SO miles, sloping gradually down from an elevation 

 of 700 to 750 feet. These dimensions, of course, vary in the different 

 parts of the valley; but what I have said will convey some idea of the 

 immense prairie watered by the Tchajisansan, which has been deemed 

 by all travellers to those distant regions perhaps the most beautiful within 

 the territory of the United States. 



I hazard, in conclusion of my remarks on the physical geography of the 

 valley just described, the suggestion that it has been scooped out by some 

 powerful denuding cause, and that its original geological character was such 

 as is now observed in the Coteau du Missouri and the Coteau des Prairies^ 

 by which it is bounded. 



It is only necessary to cast a glance over the map, to form an idea of 

 the importance of Tdian-sansan river. It takes its rise on the plateau 

 of the Missouri, beyond the parallel of 47° N. ; and after pursuing nearly 

 a north and south course, empties into the Missouri river below 43°. 

 It is deemed navigable with small hunting canoes for between 500 and 

 600 miles; but, below Otuhu oju, it will float much larger boats, and 

 there are no otfier obstades in its navigation than a few rafts. When 

 we turned away from the river in latitude 47*^ 27', its breadth was from 

 SO to 100 feet ; and we could discover by the water marks on its banks, 

 that, in the season of freshets, it widens out here to 100 yards, and south 

 of Otuhu oju to 200 yards. The shores of the river are generally toler- 

 ably well wooded, though only at intervals ; the trees consisting princi- 



