Lewis: July 20, 1806

Sunday July 20th 1806 We set at sunrise and proceed through the open plain
as yesterday up the North side of the river. the plains are more broken
than they were yesterday and have become more inferior in point of soil; a
great quanty of small gravel is every where distributed over the surface
of the earth which renders travling extreemly painfull to our bearfoot
horses. the soil is generally a white or whiteish blue clay, this where it
has been trodden by the buffaloe when wet has now become as firm as a
brickbat and stands in an inumerable little points quite as formidable to
our horses feet as the gravel. the mineral salts common to the plains of
the missouri has been more abundant today than usual. the bluffs of the
river are about 200 feet high, steep irregular and formed of earth which
readily desolves with water, slips and precipitates itself into the river
as before mentioned frequentlly of the bluffs of the Missouri below which
they resemble in every particular, differing essencially from those of the
Missouri above the entrance of this river, they being composed of firm red
or yellow clay which dose not yeald readily to the rains and a large
quantity of rock. the soil of the river bottom is fertile and well
timbered, I saw some trees today which would make small canoes. the timber
is generally low. the underbrush the same as before mentioned. we have
seen fewer buffaloe today than usual, though more Elk and not less wolves
and Antelopes also some mule deer; this speceis of deer seems most
prevalent in this quarter. saw some gees ducks and other birds common to
the country. there is much appearance of beaver on this river, but not any
of otter. from the apparent decent of the country to the North and above
the broken mountains I am induced to beleive that the South branch of the
Suskashawan receives a part of it’s waters from the plain even to the
borders of this river and from the brakes visible in the plains in a
nothern direction think that a branch of that river decending from the
rocky mountains passes at no great distance from Maria’s river and to the
N. E. of the broken mountains. the day has proved excessively warm and we
lay by four hours during the heat of it; we traveled 28 miles and encamped
as usual in the river bottom on it’s N. side. there is scarcely any water
at present in the plains and what there is, lies in small pools and is so
strongly impregnated with the mineral salts that it is unfit for any
purpose except the uce of the buffaloe. these animals appear to prefer
this water to that of the river. the wild liquorice and sunflower are very
abundant in the plains and river bottoms, the latter is now in full blume;
the silkgrass and sand rush are also common to the bottom lands. the
musquetoes have not been troublesome to us since we left the whitebear
islands.-