May 20, 1805
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May 20, 1805


Set out at an early hour as usual, the banks being favourable and water strong we employed the toe rope principally; river narrow and croked; country much as that of yesterday; immence number of the prickley pears [1] in the plains and on the hills. At the distance of 2¼ miles passed the entrance of a large Creek, affording but little water; this stream we named Blowing Fly Creek, [2] 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. At 11 A. M. we arrived at the entrance of a handsome bold river which discharges itself into the Missouri on the Lard. side; this stream we take to be that called by the Minnetares the [blank] or Muscleshell River; if it be the same, of which I entertain but little doubt, it takes it's rise, by their information in the 1st Chain of the Rocky Mountains at no great distance from the Yellow stone river, [3] from whence in it's course to this place it passes through a high and broken country pretty well timbered, particularly on it's borders, and intersperced with handsome fertile plains and medows.    but from the circumstance of the same Indians informing us that we should find a well timbered country in the neighbourhood of it's mouth, I am induced to beleive that the timbered country of which they speak is similar to that we have passed for a day or two, or that in our view above, which consists of nothing more than a few scattering small scrubby pine and dwaft cedar on the summits of some of the highest hills nine tenths of the country being wholy destitute of timber of any kind, covered with a short grass, arromatic herbs and the prickley pear; the river bottom however, so far as we have explored it or 8 m. are well stocked with Cottonwood timber of tollerable size, & lands of excellent quality. We halted at thentrance of the river on the point formed by it's junction with the Missouri determining to spend the day, [4] make the necessary observations and send out some hunters to explore the country. The Muscle Shell river falls into the Missouri 2270 miles above it's mouth, and is 110 yards in width, it affords much more water than streams of it's width generally do below, it's courant is by no means rappid, and from appearances it might be navigated with canoes a considerable distance; it's bed is coarse sand and gravel principally with an occasion mixture of black mud; it's banks abbrupt and about 12 feet high yet never appear to overflow; the waters of this river is of a greenish yellow cast, much more transparent than the Missouri, which last is also much more transparent than below but still retains it's whiteish hue and a proportion of it's sedement.    the Missouri opposite to this point is deep, gentle in it's courant, and 222 yards in width. The hunters returned this evening and informed us that the country continued much the same in appearance as that we saw where we were or broken, and that about five miles abe [NB: above] the mouth of shell river a handsome river of about fifty yards in width discharged itself into the shell river on the Stard. or upper side; this stream we called Sâh-câ-gar me-âh [NB: Sah ca gah we a] or bird woman's River, after our interpreter the Snake woman. [5]    Shields also found a bould spring or fountain issuing from the foot of the Lard. hills about 4 miles up the Missouri; a fountain in this plain country is a great novelty; I have not seen a bould fountain of pure water except one since I left the Mandans; there [NB: are] a number of small ones but all without exception are impregnated with the salts which abound in this country, and with which I believe the Missoury itself considerably impregnated but to us in the habit of useing it not perceptible; the exception I make is a very fine fountain under the bluffs on the Lard. side of the Missouri and at a distance from the river about five miles below the entrance of the yellowstone River. The sands of the Missouri are not so abundant as they have been for some time past, being confined to the points only; the bed of the river principally mud and still too deep to use the seting pole. Capt. Clark walked out today and killed two deer and an Elk, the hunters killed 4 deer and elk and a buffaloe. I saw two large Owls [6] with remarkable long feathers on the sides of the head which resembled ears; I take them to be the large hooting owl tho: they are somewhat larger and their colours brighter than those common to the U' States.—

Courses and distances of May 20th 1805. [7]
South Along the Stard. side to the upper part of a bluff (bad water)   ½
S. 70° E. to a sand point on the Stard. side 1
S. 20° W. to some timber on a Stard. point    ½
S. 10° E. to the entrance of a large creek on Lard. 25 yds. wide, called
blowing Fly Ck.

South to a point of timher on the Lard. side opposite to a bluff on
Stard. side

1 ¼
S. 30 E. to a willow point on the Stard. side opposite to a bluff on
Lard. side

1 ¼
South along the Stard. point opposite to a bluff    ¼
West to a point of woodland on the Lard. Sd. just below which
Muscle shell R. discharges itself on the Lard. 2270 m. up

  Miles 7

Point of Observation No. 20.

On the Lard. shore opposite to the extremity of the 5th course of this day, observed time and distance of ☉'s, and ☽'s nearest limbs, with Sextant, the ☉ East.

Mean of a set of 12 observations
  Time       Distance
  h    m      s    
A. M. 9    44    48   103°    3'    14"

Longitude deduced,—    [blank]

Point of Observation No. 21. [8]

On the point of land formed by the junction of the Missouri and Muscle Shell river observed Equal Altitudes of ☉, with Sextant.

  h m   s              
A. M. 9 53 31   P.M. lost     } Altd. of Sextant
at the time of Obst.
81° 58' 15"
  " 55   6     4 40 33
  " 56 44     4 42 10
  h    m    s
Chronometer too [blank] on Mean time [blank]

Observed Meridian Altd. of ☉'s L. L. with Octant by the back observation 59° 50'

Latitude deduced from this Observation    47° 00' 24.6"

Observed also magnetic Azimuth of ☉'s Center.

Azimuth by
  Time by
  Altitude by
    h    m    s      
1st S. 85 W.   A. M.    6    14    35   50°   —'   —"
2cd S. 82 W.   "      6    24    36   46    37    30
3rd S. 80 W.   "      6    34    42   43    15    30

The variation of the magnetical needle.    [blank]


a fine morning    wind from the N E.    river falling a little    We Set out at 7 oClock and proceeded on verry well as usial by the assistance of the Cord    passed Some verry Swift water, river narrow and Crooked, at 11 oClock arrived at the mouth of Shell river on the Lard Side and formed a Camp for the present.    haveing passed a large Creek about 4 miles below on the Ld Side which we call Blowing fly Creek from the emence quantites of those insects which geather on our meat in Such numbers that we are oblige to brush them off what we eate.

muscle Shell River falls in on Lard Side 2270 miles up    Contains a greater perportion of water than Rivers of its Size below, I measured it and find it to be 110 yards wide, the water of a Greenish yellow Colour, and appers to be navagable for Small Craft, The Minetarras inform us that this river heads in the 1st of the rockey Mountains & passes through a broken Countrey.    its head at no great distance from the Yellow Stone River    The Countrey about this river as described yesterday    we took the Meredian altitude 59° 50' 0" back observation and found the Latd. to be 47° 0' 24"

〈The Distance of the Moon's Western Limb〉

Observed time & Distance of Sun & Moons nearest limbs    the Sun East

  Time   Distance
  h    m     s    
A. M. 9   39    17   103°  5'   15"
  "    40    26   103   4    45
  "    41    17     "      4    15
  "    42    45     "      4      0
  "    44      0     "      3    30
  "    45      2     "      3    15
  "    45    50     "      3      0
  "    46    51     "      2      0
  "    47    53     "      2      0
  "    48    57     "      1    45
  "    50    22     "      1    30
  h    m    s
Cronometer too fast mean time [blank]

observed Equal altitudes with Sextent

  H M S } altitude produced from this observation is 81° 58' 15"
A M 9 53 31
  " 55   6
  " 56 44
P M "   "   "
  4 40 33
  4 42 10

Took the Magnetick azmoth of the Sun

  Cours       Time       Distance
      h    m      s    
P M S 85° W   6    14    35   50°   00'   00"
  S 85° W   6    19    31   48    20    15
  S 82° W   6    24    38   46    37    30
  S 80° W   6    34    42   43    15    30

The Missouri at the mouth of Shell River is 222 yards wide with a Smoth Current    the Missouri water is not So muddey as below, but retains nearly its usial Cholour, and the Sands principally Confined to the points    I killed two Deer & an Elk, the hunters killed an Elk & Several deer mearly for their Skins to make Leagins,—    Sent men out in every derection, the Countrey generally verry broken Some leavel plains up the Shell river The bottoms of the Shell river is well timbered as also a Small river which falls into that river on the upper Side 5 miles above its mouth. The hills on the Lard. Contain Scattering Pine & Cedar.

  mile Course & Distance May 20th 1805
South    ½ allong the Stard. Side to the upper part of a Bluff (bad
S. 70° E 1 to Sand point on the Stard. Side
S. 20° W    ½ to the timber on the Stard. point
S. 10° E    ¼ to the enterence of a large Creek Lard Side
South 1 ¼ to the point of timber on the Lard Side opposit a Bluff S. S.
S. 30° E 1 ¼ to a willow point on the Stard Side opposit a bluff on the
Lard Side
South    ¼ allong the Std. Point opsd. a bluff
West 2    to a point of wood land on the Lard. Side below which the
mouth of Shell river falls in on the Lard. Side 2270 up
miles 7  

Monday 20th May 1805.    a clear pleasant morning.    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 [9] 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 [10]    at 11 oClock we arived at the mouth of Shell River on the Lard Side 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 47° 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 the Shell river.    the bottoms of the Shell River is well timberd as also a Small river [11] 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)


Monday 20th.    We set sail early and had a fine morning. Passed a creek on the south side [12] 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 47° 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.


Monday 20th May 1805.    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. 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 47° 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.

Monday May 20th    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 47° 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—

1. Opuntia polyacantha Haw. var. polyacantha, plains prickly pear. Barkley, 49; Benson (CUSC), 382—88; Booth & Wright, 160. (back)
2. Later Squaw Creek, in Garfield County, Montana. Atlas maps 39, 51, 59; MRC map 69. The blowing fly may be from either Calliphoridae or Sacrophagidae families. Someone drew a vertical line through this passage, from "this stream" to "we eat." (back)
3. Musselshell River, here dividing Garfield and Petroleum counties, Montana, still bears the name the captains gave it, translating the Hidatsa name (see Fort Mandan Miscellany). It rises in the Castle Mountains in Meagher County, Montana, within one hundred miles of the Yellowstone River. Atlas maps 39, 43, 51, 59; MRC map 69. (back)
4. In either Garfield or Petroleum County, on the upstream side of the Musselshell's earlier mouth, on a site now covered by Fort Peck Reservoir. Atlas maps 39, 43, 51, 59; MRC map 69. (back)
5. The stream, in Petroleum County, was for many years called Crooked Creek; it has since been renamed Sacagawea River. Atlas maps 39, 51, 59; MRC map 69. Sacagawea herself is discussed at the entry of November 4, 1804. Thwaites gives the reading for Sacagawea's name as "Sâh-câ-ger we-âh" and attributes the interlineation to Biddle; Coues reads it as "Sâh-câ-gee-me-âh" and attributes the interlineation to Clark. The syllable "gar" could easily be read "ger," but Thwaites's reading of "we" for the fourth syllable is difficult to accept. The syllable might also be read with a capital "M." Thwaites (LC), 2:52; Coues (HLC), 1:317 n. 38. See also Anderson (SSS). Biddle made some other marks in red besides the bracketed material: he crossed out "Sâh-câ-gar me-âh" and placed parentheses around "or bird woman's River." Perhaps it also was he who drew vertical lines through passages from "which consists of" to "tollerable size" and "I saw two" to "U' States." (back)
6. Probably the Montana horned owl; see above, April 14, 1805, and Burroughs, 208–9. Holmgren identifies it as the long-eared owl, Asio otus [AOU, 366]. Holmgren, 32. (back)
7. Also given on Atlas map 39, in both captains' hands. (back)
8. A nearly identical observation is found in Lewis's astronomy notebook (see Appendix C). (back)
10. From this sentence to the end of the entry Ordway is largely copying from Clark. He continued to do so for the next two weeks. That Ordway is doing the copying and not Clark seems apparent from his use of such words as "larboard" and "starboard," where the sergeant would normally use "south" and "north." (back)
11. Today's Sacagawea River, Petroleum County, after the party's name and honoring Sacagawea, the Shoshone interpreter. (back)