Jefferson/Beaverhead River near present-day Dillon — Patrick Gass: August 10, 1805

proceeded on through the valley, until breakfast time,
when we came to a place where the river passes through a
mountain. This narrow passage is not more than a quarter
of a mile in length. At the upper end another valley com-
mences, but not so wide as the one below. There is no tim-
ber in the lower end of this valley ; and the river very crooked,
narrow, and in some places so shallow, that we were obliged to
get into the water and drag the canoes along. At 1 o’clock
we halted to dine, when a shower of rain came on with thun-
der and lightning and continued an hour, during which some
hail fell. Two hunters were out to-day and killed but one
deer. We came 13 miles and encamped on the North side.
Here the valley begins to be more extensive.