elivation

This morning I dispatched Joseph Fields up the yellowstone river with orders to examine it as far as he could conveniently and return the same evening; two others were directed to bring in the meat we had killed last evening, while I proceeded down the river with one man in order to take a view of the confluence of this great river with the Missouri, which we found to be two miles distant on a direct line N. W. from our encampment. the bottom land on the lower side of the yellowstone river near it's mouth for about one mile in width appears to be subject to inundation; while that on the opposite side of the Missouri and the point formed by the junction of these rivers is of the common elivation, say from twelve to 18 feet above the level of the water, and of course not liable to be overflown except in extreem high water, which dose not appear to be very frequent there is more timber in the neighbourhood of the junction of these rivers, and on the Missouri as far below as the White earth river, than there is on any part of the Missouri above the entrance of the Chyenne river to this place. the timber consists principally of Cottonwood, with some small elm, ash and boxalder. the under growth on the sandbars and verge of the river is the small leafed willow; the low bottoms, rose bushes which rise to three or four feet high, the redburry, servicebury, and the redwood; the high bottoms are of two discriptions either timbered or open; the first lies next to the river and it's under brush is the same with that of the low timbered bottoms with the addition of the broad leafed willow, Goosbury, choke cherry, purple currant; and honeysuckle bushis; the open bottoms border on the hills, and are covered in many parts by the wild hyssop which rises to the hight of two feet.

William Clark - The Journals of Lewis and Clark, 1804-1806