(This essay first appeared in Montana: The Magazine of Western History , Volume 35, Summer 1985, pgs. 28–39.)
The journals of the Lewis and Clark expedition are one of our country's national treasures. These diaries, written by the two captains and four enlisted men, contain over a million words. The breadth of these writings is unmatched by any similar enterprise, and the depth of the leaders' observations and insights has been universally admired. The careful record of daily activities, the extensive scientific observations of plants, animals, weather, and terrain, and the writing style with its charming peculiarities in spelling, grammar, and punctuation make the journals the hallmarks of that great voyage of discovery. On those records rest all the expedition's claims to greatness. The men set a standard of record-keeping for later expeditions and left a literary heritage for the ages. In large measure, the scope and quality of the documents account for much of the continuing fascination in the Lewis and Clark story.
Despite the quantity of the Lewis and Clark legacy in field notes, notebook journals, field journals, and scraps of diary writings, there persists a nagging question: Is the record complete?
Over the years, numerous documents of the expedition have come to light, some in the most unexpected places. In 1903, Reuben Gold Thwaites, editor of the centennial edition of the journals, discovered unknown Clark diaries and papers in the possession of Clark's descendants; in 1915, Sergeant John Ordway's journal and Lewis and Clark's Eastern Journal were found among the papers of Nicholas Biddle, editor of the 1814 paraphrase of the journals; in 1953, Clark's Field Notes were discovered in an attic roll-top desk in St. Paul, Minnesota; and as recently as 1966, a fair copy of Private Joseph Whitehouse's journal, which extended the narrative almost five months, appeared in a bookstore in Philadelphia.
These discoveries seem to support the notion of other lost items yet to be found. No hope of discovery ranks so high as the hope of finding Meriwether Lewis's diaries, which would fill the large gaps in his writing during and about the expedition. This essay looks at Lewis's known journals, considers where gaps might be filled with the discovery of new materials, and concludes that there are few possibilities of new finds. To a large degree, these considerations are interpretative and speculative and the conclusions are tentative. We can only hope that more of Lewis's writings are still to be found.
The gaps in Lewis's writings are numerous and extensive. They include missing days from the trip on the Ohio and Mississippi rivers from September 19 to November 11, 1803, a nearly complete lapse from May 14, 1804, to April 7, 1805, only spotty entries from August 26, 1805, to January 1, 1806, and a final hiatus from August 12, 1806, to the completion of the expedition. The last gap can be explained by Lewis's being partially disabled from a wound; in contrast to other lapses in writing, he noted at the time that he was laying down his pen. One might also include the period from November 28, 1803, to May 14, 1804, during the winter in the St. Louis area, a time for which no Lewis journal is known. Clark at least kept a rough diary during that time. In all, from May 1804 to September 1806, there are over four hundred days of missing entries by Lewis during the expedition proper. 
Lewis seems to have displayed a pattern of laxness in consistent journal-writing from the start. He began a diary, the Eastern Journal, when he left Pittsburgh in August 1803 on his way down the Ohio River to St. Louis. From September 19 to November 11, however, he made no entries and left thirty-nine pages blank in the notebook between these separated entries, perhaps with the intention of supplying the missing information later. Lewis never filled in the gap, which suggests that he probably had no preliminary notes to furnish the missing material.  He certainly had ample time to supply the omitted information during the five months that he spent in the St. Louis area preparing for the expedition. Lewis returned to his journal writing on November 11 but gave the journal to Clark on November 28 near Kaskaskia, as the two captains separated, Lewis going ahead by land to St. Louis while Clark led the boat party forward to establish Camp Dubois. From that point on, Clark's faithful journal-keeping provides us with a nearly complete record.
Lewis may have felt no need for a full journal account because he was traveling across well-known terrain from Pittsburgh to St. Louis and because he was corresponding with President Jefferson about his travels. Administrative duties in preparation for the expedition, which kept Lewis away from the party's camp, and the knowledge of Clark's diary may account for the lack of a diary during that first winter. Lewis's early lapses may be the result of his view that the expedition, at least at that point, had not actually begun.
More difficult to explain is Lewis's lack of journal-keeping once the expedition got underway. No Lewis journals are known to exist that cover the first phase of the expedition, from May 14, 1804, until the group left Fort Mandan on April 7, 1805. This is the longest hiatus in Lewis's writing and to historians it is the most curious gap. It is particularly bewildering because one would expect Lewis to be more conscientious at the outset of the expedition, especially considering Jefferson's explicit instructions about the keeping of multiple journals. Jefferson admonished Lewis: "Several copies ... of your other notes should be made at leisure times, & put into the care of the most trust-worthy of your attendants, to guard, by multiplying them, against the accidental losses to which they will be exposed."  Some observers, incredulous that this gap exists, have speculated that Lewis was probably keeping field drafts or standard journals of the party's activities—notes that have since been lost.
The captains wrote in a variety of notebooks during the expedition. Most of them are five- by eight-inch, morocco-bound books that open from the end—the socalled red books. There are also four notebooks bound in pasteboard with marbled covers, a couple of leather-bound books, and one field book made from loose sheets and bound in elkskin. In 1893, Elliott Coues codified most of this material, at least that which was available to him at the American Philosophical Society, and labeled the journals Codex A, Codex B, and so on. To say that Lewis was keeping no journal in such form from the outset is not precisely correct. There exist two small fragments for the dates May 15 and May 20 and September 16–17, 1804, which Coues labeled codices Aa and Bb. These sheets, apparently torn from one of the red books, suggest to some that Lewis was keeping a journal for the initial period and that the remaining pages were discarded because they were soiled, ruined, or unnecessary. Or perhaps the remaining pages are simply lost. Another explanation seems plausible: the two codices are singular and not a rescued portion of a larger whole.
In the case of Codex Aa it is noteworthy that the order of days is reversed: the entry for May 20 precedes the entry for May 15, with no break between the two. The entry for May 20 recounts Lewis's activities for that day as he set out by land from St. Louis for St. Charles where he was to rendezvous with Clark, who was leading the party upriver. He also reported on the activities of Clark's party. Perhaps Lewis saw this entry as the beginning of his journal-keeping, since the captains had previously determined to set out on May 21. If this is true, then why the addition of notes for May 15? A more detailed report of Clark's trip upriver, written as if Lewis had been present, the May 15 entry presents more information than Clark has for that day in either of his two accounts. Lewis probably got this information directly from Clark. Perhaps Lewis thought he ought to add an entry for May 15 to give a more detailed account of the actual start of the expedition. Although Clark set out from Camp Dubois on May 14, the men had earlier decided on May 15 as the date to begin, and perhaps Lewis still had that date in mind. The entry of May 15 stops in mid-page, seeming to indicate that nothing followed.
Codex Ba presents a different situation. On September 16 and 17, 1804, the group was encamped at "Corvus" Creek just above today's White River in South Dakota. While there, the leaders changed plans and decided not to send a pirogue back to St. Louis with artifacts and other items representing their journey thus far. Perhaps Lewis had planned to send their notes to St. Louis along with the other materials, knowing that everything would eventually reach President Jefferson. Thus, Lewis may have considered that he was now beginning a journal, in a sense the first for him since he had apparently quit writing after his May 15 entry. But having made the decision not to send a boat and crew back, he may have ceased his journal writing (indeed, he stopped at mid-page in mid-sentence) and perhaps decided not to write again until after the winter at Fort Mandan. Clark also may have had some notion of a shift in writing here. A note on one sheet of his Field Notes after the September 16 entry reads: "refur to the Book No. 2." The book would be his Codex B, and the note could signify his intention to abandon his Field Notes in favor of keeping only a notebook journal.
Some writers have supposed that Lewis was keeping field notes similar to Clark's during the trip from Camp Dubois to Fort Mandan and that he intended to use that material to fill regular notebooks later. Other persons might consider the fragments for May and September as part of a complete set of notes from a regular notebook that is now lost. Donald Jackson has made the strongest case for Lewis having kept a journal during the first leg of the journey, but he emphasizes the speculative nature of his conclusions. Jackson believes that a mishap on May 14, 1805, may indicate a loss of journals. On that day, one of the pirogues turned on its side, filled with water, and soaked some papers and notebooks. Jackson discovered that within a few days of the accident Clark began conscientiously copying Lewis's natural history notes into his own journal, something he had not previously done. Jackson argues that the spoilages may have been greater than the leaders first realized, convincing the men that duplicate records were necessary, not just multiple diaries. He also conjectures that "perhaps Lewis's notes for the entire first leg of the expedition were either badly water-soaked or entirely lost." Thus, Jackson believes that the entries by Lewis for May and September 1804 are fragments of a larger journal from that early period. 
Reuben Gold Thwaites also thought that Lewis was a regular journal-keeper, but his reasoning is less plausible than Jackson's. Thwaites supposed that the journals might have been lost after Lewis's death in Tennessee in 1809. Surely Clark or Jefferson would have bemoaned so serious a loss, but neither man ever made reference to it in any known source. Jackson speculates that there is no mention of the supposed loss of journals in May 1805, because Lewis would have told Jefferson about the accident after his return and that there was no need to announce it to the world in his diary. 
Postulating about the writing of field notes by either man in cases where none has been found and where there is no strong evidence of their having existed seems unwise. Further, it is not necessary to believe that for every finished journal there was a preliminary set of field notes nearly duplicating it. Theories involving the existence of such notes ought to be avoided unless clear evidence requires them. The sheer amount of labor involved in composing multiple sets of notes and journals argues against such suppositions and, in fact, no field notes for Lewis have ever been discovered. What miscellaneous items that have been found hardly compare to Clark's Field Notes or to his later field book, the elkskin-bound journal that describes activities from September to December 1805. Still, considering the history of journal discoveries to date, no one can assert with certainty that there are no lost notes or journals or that none will ever be found.
Those who think Lewis kept a journal or field notes during the trip to Fort Mandan have found strong evidence in letters from Lewis and Clark to Jefferson just before the party set out from that post. The opening phrase of Clark's letter has been struck out and other words substituted by Lewis. Clark wrote, "As Capt. Lewis has not Leasure to Send 〈write〉 a correct Copy journal of our proceedings &c.," and Lewis substituted, "It being the wish of Capt. Lewis." Those who argue that Lewis kept a journal interpret Lewis's change to mean that he had not converted field notes into an acceptable journal or that he had not completed a journal on hand. There are other ways to read the excised parts: Did Lewis not have time to send his journal, did he not have time to write it, or did he not have time to make a correct copy? Lewis's letter stated that he would send a canoe with some men back from the extreme navigable point of the Missouri River (a scheme later rejected) and with that boat "I shal send you my journal." Again, one can read the phrase variously: Was Lewis to send a journal he had been keeping or one he intended to write? Only Ernest S. Osgood has concluded that Lewis kept no journal: "I do not think there is enough available evidence to support a conclusion that Lewis was keeping a journal on the first leg of the journey." But even he hesitates to dismiss the idea entirely. In another instance he writes, "Field notes ... must have been taken by both Lewis and Clark during the whole journey." Rather than speculate on a hidden meaning that can never be determined, it is probably better to examine the totality of Lewis's writing during the early period and to interpret from that perspective. 
The lack of consistent daily entries by Lewis from St. Charles to Fort Mandan does not mean that Lewis performed no writing duties during this time. Quite a bit of Lewis's writing is extant, and additional material is known to be missing. As the expedition's naturalist, he kept fairly extensive notes on the flora and fauna of the region through which the party passed. In Codex R, he made a list of herbarium specimens that he was collecting. The descriptive writing is occasionally lengthy and shows not only Lewis's powers of observation but also his record-keeping activities. His observations about animals are almost as extensive and cover over fifty pages of Codex Q. He also noted mineral deposits and geologic features along the Missouri and took astronomical observations—both time-consuming tasks that included record-keeping. And although Lewis cannot be directly credited, it is known that the captains were keeping lists of Indian vocabularies during this period, work that may have amounted to extensive note-taking. The vocabularies are the missing material that might include additional writing by Lewis.
From January to May 1804, Lewis also kept a weather diary in a separate little notebook. These observations are repeated in Clark's Codex C, and it may be that Lewis was copying Clark's entries. After May 14, there is a gap of weather data in both the men's books until September 19; the notations are then resumed with hardly an interruption until April 3, 1805, when Lewis began including weather data in his daily entries. It may be significant that September 19 is the date of again taking up the weather notations, since it is about the time Codex Ba was begun and when the captains decided not to send pirogues back to St. Louis. If Lewis was keeping the weather diary independent of Clark and Clark was copying the weather data into his Codex C, then there may be missing field notes, at least Lewis's remarks on weather during this period. The weather notes indicate a substantial amount of writing because they consist of two temperature readings for each day, the general state of the weather, the wind direction, and the rise and fall of the river. There are also comments on natural history, including sightings of animals and the budding and fading of flora. It is uncertain whether Lewis made the notes on his own along the way or copied from Clark's journal at the time or at Fort Mandan. In either case, it was a collaborative effort.
There is the potential for more extensive writing by Lewis. A single loose sheet from Clark's Field Notes is entirely in Lewis's hand and contains on one side a draft for his description of the Platte River, which he later transferred into Codex O as his survey of rivers and creeks. Although there is a date of July 21 (1804) on the document, the reverse contains lunar observations (also in Lewis's hand) for February 23, 1805, while the party was at Fort Mandan. It could be that the draft describing the Platte was copied into Codex O at Fort Mandan. The draft from the Field Notes is incomplete, so it is certain that other pages are missing, but whether these pages describe only the Platte or contain a full draft of his summary may never be known. If Lewis was keeping thorough topographical notes such as these throughout the first portion of the trip, it helps explain why no daily entry material is to be found. It may simply have amounted to too much writing.
One incident on the way to Fort Mandan may corroborate the notion that Lewis kept no journal of daily events during that period. On July 14, 1804, a sudden storm hit the river and great gusts of wind turned one boat on its side and it began to fill with water. Cool heads and quick action saved the vessel from destruction, but Clark reported that his notes of the previous day had blown overboard during the accident. Clark mentioned that the loss "obliges me to refur to the 〈notes〉 Journals of Serjeants, and my own recollection [of] the accurences Courses Distance &. of that day." If Lewis had been keeping a journal of events during this time, why would Clark go to the journals of the sergeants or depend on his own recollection for the "accurences"? Certainly he would have trusted Lewis's notes over his memory or the notes of enlisted men if any journals by Lewis had been available. 
Taken together Lewis's recording activities up to Fort Mandan add up to a large amount of "journalizing" and may represent a proportional share of the writing duties of the captains. What emerges is a picture of the two men sharing journal-keeping chores, though not following Jefferson's prescription to the letter. It strains credulity to believe that all of Lewis's daily entry journals (except for a few pages of writing for May and September 1804) from St. Charles to Fort Mandan and during the winter of 1804–1805 could be lost. Clark filled three notebooks of writing for that period, and Lewis, the more verbose, would have written even more. Short of discovering actual journals by Lewis or definite references to such writing, one must suppose that he kept no record of daily events for this portion of the expedition. 
From the expedition's departure from Fort Mandan on April 7, 1805, to late August 1805, complete notebook journals for both captains exist, with no fragmentary or parallel journals until August, although the two leaders copied each others' writings. There is no indication that either of them followed Clark's earlier practice of writing field notes and transferring them, with revisions, into notebook journals. Indeed, there is no reason to assume that the captains consistently followed any one plan or procedure throughout the expedition. Their responsibility was to keep as complete a record as possible of the many kinds of information that Jefferson wanted and to preserve that record from harm or loss. They could follow any procedure that suited their convenience and the conditions of the moment, so far as was consistent with this mission. Conditions varied so much throughout the trip that there was every reason to change journal-keeping procedures. When they were inconsistent in so much else, there is no reason to expect them to be consistent in how they kept their journals.
Duplication of journals served as insurance against loss or damage, but with both men keeping journals after April 7, 1805, there would have been less need for keeping both field notes and notebook journals, a time-consuming task. Field notes would be of value, however, in situations where there was an increased risk of damage or loss from weather or difficult travel conditions, where it seemed wise to put away the notebooks and keep field notes easily accessible. Such precautions might also be taken when one of the captains was scouting ahead on foot, accompanied by only a few men; he might leave his notebook journals with the main body, both for convenience and for safety. After such separations, one leader might copy the experiences of the other into his own journal to ensure the preservation of a complete record.
As they moved up the Missouri around the Great Falls, the captains were separated at various times in June, July, and August 1805, as one or the other was ahead, portaging the falls or later looking for the Shoshoni Indians. During these intervals, Lewis sometimes copied Clark's journals for the days of separation under the date of their reunion, which suggests that he was keeping the notebook journal day by day. At other times, Lewis gave an account of Clark's activities in his own entries for each day, which indicates that these entries must have been written after they were reunited. During this period, Clark did not ordinarily copy Lewis's record of daily events while they were separated. 
By late August, Lewis's journal writing began to fall off. His journal entries became very sporadic and raise a different set of questions about his journal-keeping activities. There are four fragmentary journals by Lewis from August and September 1805, which Coues designated codices Fa, Fb, Fc, and Fd. Each consists of a few loose sheets covering periods of from two to five days. Codex Fa describes events that are related in more detail in Lewis's regular journal, Codex F (July 17–August 22, 1805). The other codices are all from periods after the end of Codex F, during a hiatus of over four months for which there are no other known Lewis journals, except for a later fragment, Codex Ia (November 29–December 1, 1805).
It is tempting to regard the little diaries as being literally "fragments," that is, portions of a lost body of field notes or regular journals by Lewis covering perhaps the entire gap in his journal-keeping from late August 1805 to January 1, 1806. But the fragments themselves provide no evidence for this hypothesis. If they included portions of a previous day's entry at the beginning or of the next day's entry at the end, there would be good reason to regard them as portions of a larger body of lost notes. On the contrary, they appear to be complete in themselves. At the end of an entry in Codex Fa, for example, there is a dated heading without a following entry. Only a blank space follows the date on the last sheet of the codex. Moreover, all of the fragments except Fc relate to periods when the leaders were separated: Fa chronicling a scouting excursion ahead of the main body when Lewis might have preferred not to risk his notebook journal, the other two describing periods when Clark scouted ahead and Lewis had to keep a record of the movements of the main party. Codex Fc derives from two days of relative leisure for the expedition at Travelers' Rest in western Montana when Lewis may have intended to resume journal-keeping after a lapse of about two weeks. Perhaps Lewis started Codex Fc in the middle of a blank book (Codex P) because he intended to fill in the space left with his journal entries for the two weeks after August 26, the last date in Codex Fb. If so, he surely must have had notes of some kind on which to base the entries, but none are extant. Apparently he never got around to it, and there is no sign that he continued writing after September 10, at least not in Codex P. Lewis's later Codex Ia (November 29–December 1, 1805) also covers part of a period of separation and gives no indication of being part of a larger whole.  Again, we should ask why it is necessary to assume missing journals without evidence and with creditable explanations to the contrary.
Lewis began a new journal (Codex J) on January 1, 1806, and continued writing until August 12 when he laid his pen down, ending his record of the expedition. As far as is known, this was the first journal writing by him since August 1805, except for the scattered fragments. Perhaps this is another point of beginning, as has been conjectured with codices Aa, Ba, and Fc. In this instance, at least, he fulfilled his good intentions of journal-keeping (combined perhaps with a New Year's resolution). Codex J is a detailed record, to March 20, of life at Fort Clatsop. It contains extensive descriptions of local flora and fauna and the life of the nearby Indians, with numerous illustrations. Nowhere else did Lewis devote more time and record so much in fulfilling the scientific objectives of the expedition. All of his observations are incorporated in the daily entries, generally after the record of the day's events. In what was evidently an additional measure to ensure the preservation of this material, Clark copied most of it into his journals almost verbatim. For some reason, Clark did not always copy this material under the same date as Lewis had, and sometimes he placed it under an entry several days earlier than Lewis's. 
Interestingly, Lewis's Codex J includes natural history material appropriate to the Rocky Mountains and Interior Basin, notes additional to the few fragments extant for that period. If Lewis had a journal for that period (August through December 1805), why copy it into daily entries for the time at Fort Clatsop? Why not copy it into a separate journal covering the actual dates? These are questions that we cannot answer. There must have been some sort of natural history field notes or other journals for that period that are now lost. Perhaps they were similar to codices Q and R from the first leg of the expedition and not daily entry journals in the usual sense. If Lewis did have notes in daily journal form covering the August–December gap, why did he not copy them into his own journal at Fort Clatsop when he would have had time? One answer might be that the notes he had were mainly natural history and ethnographic material and that he did copy them and they went into Codex J under current dates. 
Having returned to Travelers' Rest, the leaders split the party on July 3, Lewis going northeast to seek a shorter route to the Missouri River, Clark southeast to explore the Yellowstone River. By all previous experience, Lewis should have kept a journal during the period of separation, especially since he would be covering territory previously unexplored by the party.
Lewis's Codex L runs to July 4, then resumes after eighteen blank pages with an entry for July 15; in no other expedition notebook journal is there such an unfilled gap in time. The fragmentary Codex La (July 3–15) covers this period, and Lewis probably intended it as the first draft. He probably packed away the notebook, Codex L, for safekeeping while traveling through the mountains, then resumed writing in it on July 15, leaving the blank pages to fill in later from the material in Codex La. He never got around to this, probably because he quit writing entirely on August 12, by which date all the writing in Codex L was probably complete. He probably wrote his account of the violent encounter with the Piegan Blackfeet on July 27–28 at least a few days later, after he had rejoined his party following a hurried ride across country. He continued Codex L to August 8, after which the fragmentary Codex Lb covers August 9–12; on August 12, Lewis stopped writing entirely because of discomfort from the accidental gunshot wound inflicted by Pierre Cruzatte the day before. He had rejoined Clark and his group on August 12, and Clark could now keep a record for the whole party.
The loose pages, which constitute Codex Lb, evidently were once part of a red notebook found among Clark's papers by Thwaites, which bears on its cover the notation "9 to 12 Augt. 1806"; it now contains no material about the expedition. Lewis evidently began writing in this book after finishing Codex L, then stopped after a few days because of the pain of his wound. In later years, Clark removed these few pages to use the book for other purposes. Considering the unfilled gap in Codex L, it appears that Lewis's journal-keeping ceased entirely on August 12, 1806, and was then complete as it now stands.
Nine of Lewis's fragmentary codices (Aa, Ba, Fa, Fb, Fc, Fd, Fe, Ia, and Lb) are apparently pages taken from notebooks, all but one (Ia) from red books. It is possible that Lewis removed these pages before writing on them, but it is equally possible that he wrote in the books and the pages were removed at some later period. Codex Fc, for instance, came from Codex P, and there is reason to believe that those pages were not removed until 1810, when the book was used to copy natural history notes for Benjamin Smith Barton. Many of these fragments represent periods when the captains were separated or when weather and travel conditions posed a special risk to the journals. On such occasions, Lewis may have used a book that was largely blank, containing perhaps some relatively unimportant or duplicated data. Thus, if the books he was carrying with him were damaged by weather or a dip in a river or if he failed to return from a scouting mission, important material would not be lost, as would be the case if he used a regular daily journal. This may strengthen the likelihood that the "fragments" are complete in themselves, and not part of a body of lost field notes.
Jefferson's references to the red books as "travelling pocket journals," although he was not present when they were written, at least suggests that some of them were at some times carried on the person.  They were small enough to carry in a pocket. The "fragment" pages could have been removed from the books during the expedition, after the return, or when Clark and Nicholas Biddle were working on the journals in 1810. If Lewis had daily field notes and did not get them copied, what happened to them? When they saved so much else—so many fragments, scraps, and sketches—why not save material by the expedition leader, covering periods when there is no other writing by him? Once again we have hypothetical lost journals for whose existence there is no real evidence.
We may assume, then, that Lewis's writings from the expedition are nearly complete. The fragments from his journal that cover the expedition from Camp Dubois to Fort Mandan are probably just that—fragments—and not part of a larger whole. Other writing helps explain a method devised by the captains for sharing writing chores: Lewis's journal entries at Fort Mandan exist only because he was filling in for the absent Clark; and the sporadic journal writing in late August and September 1805 may also be considered Lewis's stand-in writing for Clark and not portions of missing journals. Only one period provides a possibility of missing journals: from September to December 1805. Those notes, which cover mainly natural history, may be available in an existing journal, Codex J, but under different dates. Extant correspondence between Clark, Jefferson, and Biddle after the expedition, when the journals were being extensively discussed and widely sought for deposit at the American Philosophical Society, gives no indication of missing journals, although Jefferson does mention other missing material, such as the Indian vocabularies. One can only wonder at Lewis's lapses and never explain them entirely. Certainly this is not the final word on a topic that likely will never be closed, unless, of course, someone discovers Lewis's missing journals.