stream, that which came in from the north, or that which, flowing here
in a general course from southwest to northeast, was really the true
Missouri. The journal says:

"It now became an interesting question, which of these two streams is
what the Minnetarees call Ahmateahza, or Missouri, which they describe
as approaching very near to the Columbia. On our right decision much
of the fate of the expedition depends; since if, after ascending to the
Rocky Mountains or beyond them, we should find that the river we were
following did not come near the Columbia, and be obliged to return, we
should not only lose the travelling season, two months of which have
already elapsed, but probably dishearten the men so much as to induce
them either to abandon the enterprise, or yield us a cold obedience,
instead of the warm and zealous support which they have hitherto
afforded us. We determined, therefore, to examine well before we decided
on our future course. For this purpose we despatched two canoes with
three men up each of the streams, with orders to ascertain the width,
depth, and rapidity of the current, so as to judge of their comparative
bodies of water. At the same time parties were sent out by land
to penetrate the country, and discover from the rising grounds, if
possible, the distant bearings of the two rivers; and all were directed
to return toward evening. . . ."

Both parties returned without bringing any information that would settle
the point. Which was the true Missouri still remained uncertain. Under
these circumstances, it became necessary that there should be a more
thorough exploration, and the next morning Captains Lewis and Clark
set out at the head of two separate parties, the former to examine the
north, and the latter the south fork. In his progress Captain Lewis and
his party were frequently obliged to quit the course of the river and
cross the plains and hills, but he did not lose sight of its general
direction, and carefully took the bearings of the distant mountains. On
the morning of the third day he became convinced that this river pursued
a course too far north for his contemplated route to the Pacific, and he
accordingly determined to return, but judged it advisable to wait till
noon, that he might obtain a meridian altitude. In this, however, he was
disappointed, owing to the state of the weather. Much rain had fallen,
and their return was somewhat difficult, and not unattended with danger,
as the