May 20, 1805
Meriwether Lewis

this stream we named Blowing Fly Creek, from the immence quantities of those insects found in this neighbourhood, they infest our meat while roasting or boiling, and we are obliged to brush them off our provision as we eat. ... this stream we called Sah-ca-ger we-ah (Sah ca gah we a) or bird woman's River, ...

May 20, 1805
John Ordway

a clear pleasant mornng.   we Set off as usal.   one of the hunters or trapers caught a large beaver last night.   about nine oClock A.M. we passed the mouth of a large Creek [Squaw Creek.] on the S. Side & a handsom bottom of C. wood timber.   proceeded on   passed pitch pine & ceeder hills on each Side of the River.   the river narrow and crooked at 11 oClock we arived at the mouth of Shell River on the Lard Side [Musselshell River.]   and formed a Camp for the present.   the large Creek which we passed about 4 miles below on the Lard Side we Call Blowing fly Creek from the emence quantities of those insect which geather on our meat in Such nombers that we are obledged to brush them off what we eate    Mussel Shell River falls in on Lard. Side 2270 miles up    contains a greater perportion of water than River of its Size below.  Capt. Clark measured it and found it to be 110 yards wide.    the water of a greenish yallow coulour and appears to be navagable for Small crafts, the natives Inform us that this river heads in the 1st rocky mountains & passes through a broken Country.   its head at no great distance from the Yallow Stone river the Country about this river as described yesterday.   our Captains took the Meridian altitude and found the Latd. to be 47o 0 24"     the Missourie at the mouth of Shell River is 222 yds wide with a Small current.   the Missourie water is not So muddy as below but retains nearly the usal colour.   and the Sands principily confined to the points.  Capt. Clark killed two Deer and an Elk.   the hunters killed Several Elk and Several Deer, mearly for the Skins to make Leagins [and moccasons?] &.c.   Some men was Sent out in [every?] Direction    the Country generally verry broken   Some level plains up ther Shell river.    the bottoms of the Shell River is well timberd as also a Small river [Sacagawea River.]  which falls into that river on the upper Side 5 miles abo. its mouth    the hills on the Lard. Side contain Scattering Pine and ceeder but of no great value.  Small & Scrubby.--  (Came 7 miles to day)

May 20, 1805
Patrick Gass

We set sail early and had a fine morning.  Passed a creek [The expedition's Blowing Fly Creek, later Squaw Creek.] on the south side and about 11 came to the mouth of the Muscle-shell river, a handsome river that comes in on the South side.  The water of the Missouri is becoming more clear.  We here spent the remainder of the day, having come seven miles.  Captain Lewis had an observation here, which gave 47o 00 24 North latitude: and Captain Clarke measured the rivers.  The Missouri here is 222 yards wide, and the Muscle-shell 110 yards.  The water of the latter is of a pale colour, and the current is not rapid; its mouth is 660 miles above Fort Mandans.

May 20, 1805
Joseph Whitehouse

a clear pleasant morning.   we Set off as usal.   one of the hunters caught a beaver last night.   abt. nine oC. we passed the mouth of a Creek on the S.S. [Blowing Fly Creek to the expedition, now Squaw Creek.] and a handsom bottom of C. wood timber.   one of the hunters killed a Deer another killed a beaver.   we proceeded on passed pitch pine & ceeder hills on each Side River.   about 11 oClock, we arived at the mouth of Mussell Shell River on the S.S.   this River is 110 yards wide and the Missourie 222 yards wide at this place, and 2271 miles from the mouth of the Missourie River.   we encamped here on the point between the 2 rivers which is a large bottom covered with C. wood timber.   we delayed here all day for observations &c.    found the latitude 47o 24' North.   the hunters killed at this place Eight Deer 4 Elk one woolf--and remained here all the afternoon & Camped for the night    2 men Stayed out hunting beaver all night.   we came only 6 miles this morning.

May 20, 1805
Joseph Whitehouse

A Clear pleasant morning, we set off as usual, One of the hunters during last night caught a beaver; about 9 oClock A.M. We passed the Mouth of a Creek lying on the North side of the River, and a handsome bottom of Cotton Wood timber lying on the same side; We proceeded on our Voyage    at about 11 o'Clock A.M. We arrived at the Mouth of a River named by our Officers Muscle shell River, lying on the South Side of the Mesouri, this River is 110 yards wide at its mouth, and the Mesouri River; at this place 222 Yards wide; and the distance from the Mouth of the Mesouri River, to the Mouth of Muscle shell River 2,271 Miles   We took up Camp here, on a point situated between these two Rivers, in a large bottom Cover'd with Cotton wood, we halted here this day, Our Officers intending to ascertain the latitude of this place, which they compleated and found it to lay in Latitude 47o 22' North,--

The party that went out a hunting returned to us here, having killed 9 deer, one beaver, one Elk and one wolf   Two of our hunters went out this night, and stayed out all night to trap beaver.--  We came 6 Miles this morning--