The expedition reached a crisis of geography at the mouth of the Marias River, where two roughly equal streams converged and the captains could not agree which was the Missouri. On June 4, 1805, Lewis and Clark each led a small reconnaissance party up one fork. Four journals from that day survive, and read together they reveal how the same events filtered through very different eyes — a captain’s surveying gaze, a sergeant’s terse summary, a private’s camp-bound report, and Clark’s plainspoken field log.
Dividing the Party
Whitehouse, who remained at the base camp, gives the cleanest summary of the split:
Cap! Lewis & 6 men Set out to go up the Right hand fork. Cap! Clark & 5 more Set out to go up the left hand fork. they intend to go about one day & a halfs walk up the rivers & See what discoveries they can make.
Clark confirms the rosters with characteristic specificity, naming Drewyer, Sergeant Pryor, Shields, Cruzatte, Lepage, and Windsor as Lewis’s companions, and Sergeant Gass, the Field brothers, Shannon, and York as his own. Gass, writing as one of Clark’s party, simply says "Captain Clarke myself and four others went up the South branch." The arithmetic differs slightly across the accounts — a reminder that even basic head-counts vary among the journalists — but the structure of the day is consistent.
Lewis’s entry, by contrast, plunges immediately into compass bearings. From a "commanding eminence" he records the terminations of the North Mountains (N. 48° E, 30 miles), the South Mountains (S. 8 W, 25 miles), and a feature he christens the "Barn Mountain" for its resemblance to a barn roof. Where Gass and Whitehouse mark the day in plain narrative, Lewis is producing surveyor’s data.
The Same Country, Different Eyes
Both Clark and Gass note the curious near-meeting of the two streams about eight miles above the confluence. Gass writes that "the South branch and the small river which falls into the North branch, are not more than 200 yards apart," and adds the welcome detail of "a beautiful spring where we refreshed ourselves with a good drink of grog." Clark records the same geography more clinically — "the little river which falls into the N. fork is 100 yards distant only Seperated from the South fork by a narrow ridge" — but omits the grog. Gass, the enlisted man, preserves the human moment his commander leaves out.
Lewis, walking up the north fork, sees a different country and devotes his entry to natural history. He describes prickly pears whose thorns "very readily perce the foot through the Mockerson," identifies the "brown Curloos" with their distinctive landing posture, and lingers on a small lark-like bird that "rises into the air about 60 feet and supporting itself in the air with a brisk motion of the wings sings very sweetly." This is the Lewis the natural-history canon remembers — patient, precise, almost lyrical. None of the other three narrators records a single bird species for the day.
The Grizzly on the South Fork
The day’s most dramatic moment occurred on Clark’s reconnaissance, and comparing Gass’s and Clark’s accounts of it is instructive. Gass writes:
one of the men having got down to a small point of woods on the bank, before the rest of the party, was attacked by a huge he-bear, and his gun missed fire. We were about 200 yards from him, but the bank there was so steep we could not get down to his assist- ance.
Clark identifies the man and describes the proximity in vivid terms:
one of them was nearly catching Joseph Fields who could not fire, as his gun was wet the bear was So near that it Struck his foot, and we were not in a Situation to give him assistance, a Clift of rocks Seperated us the bear got allarmed at our Shot & yells & took the river.
Gass calls the animal a "huge he-bear" and says it "went off without injuring the man"; Clark names Joseph Field, specifies the wet gun, and reports the bear actually striking Field’s foot before the captain’s party drove it off with shots and shouting. Gass’s version reads as if drafted from memory or a shared retelling around the fire; Clark’s reads as the immediate report of the officer in charge. Whitehouse, back at the main camp, knows nothing of the encounter and notes only that two hunters returned with an elk and a deer.
Across the four journals, the day takes its full shape only in composite: Lewis’s mountains and birds, Clark’s bearings and grizzly, Gass’s grog and steep bank, Whitehouse’s quiet camp under a cold northeast wind. The decision about which fork was the Missouri remained unresolved that night — but the documentary record of the reconnaissance was already four-voiced.
