We set out very early this morning and continued our rout through the wide bottom on the Lard. side of the river  after passing a large creek [Blacktail Deer Creek, "McNeal's Creek," for Hugh McNeal of the party.] at about 5 miles we fel in with a plain Indian road which led towards the point that the river entered the mountain we therefore pursued the road  I sent Drewyer to the wright to kill a deer which we saw feeding and halted on the river under an immencely high perpendicular clift of rocks [Rattlesnake Clifts, found about ten miles southwest of Dillon. The cliffs are composed of early Tertiary, extrusive volcanic rocks (largely rhyolite). The rock is often badly fractured which allows it to form numerous little hollows when it weathers. These little hollows make excellent dens for snakes. The cliff west of the river rises to a height of about 600 feet above the floodplain.]  where it entered the mountain  here we kindled a fire and waited for Drewyer.  he arrived in about an hour and a half or at noon with three deer skins and the flesh of one of the best of them, we cooked and eat a haisty meal and departed, returning a shot distance to the Indian road which led us the best way over the mountains, which are not very high but ar ruggid and approach the river closely on both sides just below these mountains.  I saw several bald Eagles and two large white headed fiishinghawks [Bald Eagle, Haliaeetus leucocephalus, and the Osprey, Pandion haliaetus.] boath these birds were the same common to our country.  from the number of rattle snakes about the Clifts at which we halted we called them the rattle snake clifts.  this serpent is the same before discribed with oval spots of yellowish brown. [Prairie Rattlesnake, Crotalus viridus viridus.]   the river below the mountains is rapid rocky, very crooked, much divided by islands and withal shallow.   after it enters the mountains it's bends are not so circuetous and it's general course more direct, but it is equally shallow les divided more rocky and rapid.  we continued our rout along the Indian road which led us sometimes over the hills and again in the narrow bottoms of the river till at the distance of fifteen Ms. from the rattle snake Clifts we arrived in a hadsome open and leavel vally where the river divided itself nearly into two equal branches; [The point where Horse Prairie Creek, from the west, and Red Rock River, from the east, unite to form the Beaverhead River. Lewis considered Horse Prairie Creek the ultimate headwaters of the Missouri, but modern geographers allot this role to Red Rock River. The immediate area is now inundated by Clark Canyon Dam and Reservoir.]  here I halted and examined those streams and readily discovered from their size that it would be vain to attempt the navigation of either any further.  here also the road forked one leading up the vally of each of these streams. I therefore sent Drewer on one and Shields on the other to examine these roads for a short distance and to return and compare their information with respect to the size and apparent plainness of the roads as I was now determined to pursue that which appeared to have been the most traveled this spring.  in the mean time I wrote a note to Capt. Clark informing him of the occurrences which had taken place, recommending it to him to halt at this place untill my return and informing him of the rout I had taken which from the information of the men on their return seemed to be in favour of the SW or Left hand fork which is reather the smallest.  accordingly I put up my note on a dry willow pole at the forks, and set out up the S.E. fork, after proceeding about 1 1/2 miles I discovered that the road became so blind that it could not be that which we had followed to the forks of Jefferson's river, neither could I find the tracks of the horses which had passed early in the spring along the other; I therefore determined to return and examine the other myself, which I did, and found that the same horses had passed up the West fork which was reather largest, and more in the direction that I wished to pursue; I therefore did not hesitate about changing my rout but determined to take the western road.   I now wrote a second note to Capt C. informing him of this change and sent Drewyer to put it with the other at the forks and waited untill he returned.  there is scarcely any timber on the river above the R. Snake Clifts, nor is there anything larger than willow brush in sight of these forks.  immediately in the level plain between the forks and about 1/2 a mile distance from them stands a high rocky mountain, the base of which is surrounded by the level plain; it has a singular appearance.  the mountains do not appear very high in any direction tho' the tops of some of them are partially covered with snow.  this convinces me that we have ascended to a great hight since we have entered the rocky Mountains, yet the ascent has been so gradual along the vallies that it was scarcely perceptable by land. I do not beleive that the world can furnish an example of a river runing to the extent which the Missouri and Jefferson's rivers do through such a mountainous country and at the same time so navigable as they are. if the Columbia furnishes us such another example, a communication across the continent by water will be practicable and safe. but this I can scarcely hope from a knowledge of its having in it[s] comparitively short course to the ocean the same number of feet to decend which the Missouri and Mississippi have from this point to the Gulph of Mexico.--

The valley of the west fork through which we passed for four miles boar a little to N of West and was about 1 mile wide hemned in on either side by rough mountain and step Clifts of rock  at 4 1/2 miles this stream enters a beatifull and extensive plain about ten miles long and from 5 to six in width.  this plain is surrounded on all sides by a country of roling or high wavy plains through which several little rivulets extend their wide vallies quite to the Mountains which surround the whole in an apparent Circular manner; forming one of the handsomest coves I ever saw, of about 16 or 18 miles in diameter. ["Snake Indian Cove" otherwise Shoshone Cove in the journals; "cove" here means a narrow mountain valley. Today the village of Grant lies in the middle of it.]   just after entering this cove the river bends to the N.W. and runs close under the Stard. hills.  here we killed a deer and encamped on the Stard. Side [About 6 miles east of Grant and the junction of Montana Route 324 with the road from Bannack to the north. Lewis is about one and one-half miles above Clark Canyon Reservoir on Horse Prairie Creek.] and made our fire of dry willow brush, the only fuel which the country produces.  there are not more than three or four cottonwood trees in this extensive cove and they are but small.  the uplands are covered with prickly pears and twisted or bearded grass and are but poor; some parts of the bottom lands are covered with prickly pears sedge twisted grass the pulpy leafed thorn southernwood wild sage &c and like the uplands is very inferior in point of soil. [This ecological observation describes how the uplands and drier areas adjacent to the bottomlands are dominated by plains prickly pear, needle and thread grass, sedge (probably thread-leaved sedge), Greasewood, and Big Sagebrush, Artemisia tridentata. The vegetation is similar to that described by Lewis on July 31, 1805, but now with the addition of sagebrush which appears with increasing elevation.]    we traveled by estimate 30 Ms. today, that is 10 to the Rattle snake Clift, 15 to the forks of Jefferson's river and 5 to our camp in the cove.  at the apparent extremity of the bottom above us two perpendicular clifts of considerable hight stand on either side of the river and appers at this distance like a gate, it is about 10 M. due West.

Capt Clark set out at sunrise this morning and pursued his rout; found the river not rapid but shallow also very crooked.  they were obliged to drag the canoes over many riffles in the course of the day.  they passed the point which the natives call the beaver's head.  it is a steep rocky clift of 150 feet high near the Stard. side of the river, opposite to it at the distance of 300 yards is a low clift of about 50 feet which is the extremity of a spur of the mountains about 4 miles distant on Lard.  at 4 P.M. they experienced a heavy shower of rain attended with hail thunder and Lightning which continued about an hour.  the men defended themselves from the hail by means of the willow bushes but all the party got perfectly wet.  after the shower was over they pursued their march and encamped on the stard side. [The mountains to larboard (east) are the Ruby Range.]  only one deer killed by their hunters today.  tho' they took up another by the way which had been killed three days before by Jos. Fields and hung up near the river.

Courses and distances traveled by Capt. Clark August 10th 1805.

S. 30o W.	2	to a Clift of rocks on Stard. 150 feet high called by the natives the beaver's head. distance by water 6 1/2 miles, passing 8 bends on the Stard. side and 2 small bayous on Lard.
S. 60o W.	2	to a low bluff on the Lard. side, distance by water 6 1/2 miles, passing four islands and 18 bends on Stard. side and a low bluff and several bayous on the same side or Stard.
Miles	4

August 10, 1805
William Clark

Some rain this morning at Sun rise and Cloudy  we proceeded on passed a remarkable Clift point on the Stard. Side about 150 feet high, this Clift the Indians Call the Beavers head, opposit at 300 yards is a low clift of 50 feet which is a Spur from the Mountain on the Lard. about 4 miles, the river verry Crooked, at 4 oClock a hard rain from the S W accompanied with hail Continued half an hour, all wet the men Sheltered themselves from the hail with bushes  We Encamped on the Stard Side near a Bluff, only one Deer killed to day, the one killed Jo Fields 3 Days past & hung up we made use of   river narrow, & Sholey but not rapid.

August 10, 1805
John Ordway

a clear pleasant morning.  we Set out as usal. Several men out hunting.  we have now to live on poor venison & goat or antelopes which goes hard with us as teh fatigues is hard.  the clifts and high land begin to make near the River.   passed a high bank along L. S. took on board a deer which one of the hunters killed 2 days past.  passed a high clift of rocks on Stard. Side [Beaverhead Rock]   proceeded on the valley wider & covered with high Grass.  the hills make further from the River.  the River Small & amazeing crooked, our Commanding officers thought proper that the Missourie Should loose its name at the 2 3 forks we passed Some time ago, where we expected to have found the Snake nation of Indians. So they named the North fork Jeffersons River, the west or middle fork Maddisons River, the South fork Gallitine River, on which is a large Spring 2 miles from its Junction with the Missourie.  the Small River which falls in to Jeffersons River above the forks on L. S. they call Phillossofy River. So we Still keep on Jeffersons River   the last three forks we passed a fiew days past.  they call the North fork Wisdom River the <west or> South fork they call Philandrophy, and the west or middle Still retains the name of Jeffersons River, which we are yet on.  it is now gitting a Small Stream verry crooked and Shole in places, So that we have to wade and hall the canoes over.  about one oClock we halted to dine.  a hard Thunder Show arose of rain and large hail which lasted nearly an hour.  we then proceeded on  the prarie low & Smooth as usal.  the beaver abound in this valley which is large and extensive & pleasant &C  our hunters killed only one Deer this day.  we Came 13 miles this day and Camped on the Stard. Side.--

August 10, 1805
Patrick Gass

We set out early in a fine morning, and proceeded on through the valley, until breakfast time, when we came to a place where the river passes through a mountain. [At Beaverhead Rock along Montana Highway 41, about 12 miles southwest of Twin Bridges and 14 miles northeast of Dillon; See Lewis's entry of August 8 and Clark's entry of August 10.]   This narrow passage is not more than a quarter of a mile in length. At the upper end another valley commences, but not so wide as the one below. There is no timber in the lower end of this valley; and the river very crooked, narrow, and in some places so shallow, that we were oblighed 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 thunder and lightening, 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.

August 10, 1805
Joseph Whitehouse

a clear pleasant morning.   we Set out as usal.  Several hunters out on shore.  we now begin to live on fresh meat & that poor venson & goat meat at this time. as our fatigues [are] hard we find that poor meat alone is not Strong diet, but we are content with what we can git.   the high land make near the River on each Side.   passed a high clifts of rocks on S. Side.    proceeded on the valley gits wider and the hills make further from the River    our officers thought proper that the Missourie Should loose its name at the 2nd forks we passed Some time ago where we expected to have found the Snake nation of Indians.   So they named the North fork Jeffersons River, the west or middle fork Maddison River, the South fork Gallitine River, on which is a most beautiful Spring abt 2 mls. from its mouth.   the Small River that puts in above the forks to Jeffersons River they call phillosify River. So Jeffersons River is the one which we Still keep on. the last 3 forks they call the North fork, Wisdom R. the South Philandrophey and the west or middle fork Still retains its name Jeffersons River     it is now gitting Small crooked & Shole in places So that we have to waid and hall the canoes over.    about one oClock we halted to dine.    had a hard Thunder Shower of large hail and rain   thin proceeded on the bottom and river as usal.   the hunters killed only one deer this day.    Came 13 miles this day and Camped [Above Beaverhead Rock.] on the Stard. Side.--

August 10, 1805
Joseph Whitehouse

This morning clear & pleasant, several of our Hunters went out early to hunt, & we set out as usual, We now have nothing to live on, but fresh meat, & that poor Venison & Goats flesh, and our men seem much fataigued; and find that meat only, is too weak a diet, for men undergoing so much fataigue; but they seem all content with what we can get.   The high land makes in near to the River on both sides of it, We passed a high clift of Rocks, which lay on the South side of the River, and Valley, which seem wider, than those which we passed Yesterday, and the hills lies off farther from the River, Our officers were of oppinion (before Captain Lewis left us) that the Mesouri River should lose its name, at the place where the Second fork enter'd this River; which we passed some days past, and where we expected to have found, the Snake Nation of Indians.    they named the North fork Jefferson River, The West or middle fork Maddison River, and the South fork Gallatin, River, on whichlies a most beautiful spring of Water, about 2 Miles from its mouth; the small River, that puts in above those three forks, to Jefferson River, they named Philosophy river, so that the River that we are now on, is Jefferson River, they also named the last three forks   the North fork they called Wisdom River, & the South fork, Philanthropy River, the middle fork still retaining the name of Jefferson River (and its course runs near West).   The River at this place is narrow, crooked, and very shallow; and in many places, we had to go into the water, and hawl our Canoes along the Shore.--   About 1 o'Clock P. M. we halted to dine, and soon after we had a hard thunder Shower, and large hail.--    At 3 o'Clock P. M. we proceeded on, and passed some bottom land, lying along the River, which ere as usual rich Soil.   In the Evening we encamped in a bottom of timber'd land, lying on the River, on the North side having come 13 Miles this day.--   Our hunters returned to us here having killed One deer, which they brought with them.