Lewis and Clark as Physicians




Founded 24 January 1895

Meeting Number 1758

4:00 P.M.

February 14, 2008

Lewis and Clark as Physicians”

Boyd A. Nies, M. D.

Assembly Room, A. K. Smiley Public Library


Lewis and Clark served as physicians as well as commanders for the Corps of Discovery during their round trip expedition from St. Louis to the Pacific Ocean in 1804-6.

Many illnesses and injuries were encountered during that journey.  These included boils, abscesses, fevers, broken bones, joint dislocations, eye problems, gastrointestinal disorders, dehydration, musculoskeletal disorders, venereal disease, frostbite, foot problems, respiratory infections, and gunshot wounds. Most of those conditions were treated successfully by the Captains despite their lack of formal medical training and the near absence of effective medications. Only one man died, from a condition that probably could not have been treated successfully under any circumstances in that day.

Considering the lack of resources at their disposal, Lewis and Clark did a remarkable job as physicians.

Key Words: Lewis and Clark

Background of the Author

Boyd A. Nies was born and raised in Orange, California.  He graduated from Stanford University in 1956 and from the Stanford University School of Medicine in 1959.  An internship and residency in internal medicine at the UCLA Medical Center and the Wadsworth Veterans Administration Hospital was followed by sub-specialty training in medical oncology at the National Cancer Institute in Bethesda, Maryland and hematology at the Stanford University Medical Center.  From 1965 to 1995, he practiced hematology and medical oncology in Redlands and San Bernardino.   He subsequently was the Medical Director of the St. Bernardine Hospice for 2 years.  During retirement he has been a board member of the Watchorn Lincoln Memorial Association, the Friends of A. K. Smiley Public Library, and the Blood Bank of San Bernardino and Riverside Counties, as well as serving on many committees and boards of the First United Methodist Church. He has been married to the former Helen Salter for 50 years.  They have 3 children: Nancy, Linda, and Boyd, Jr., and 5 grandchildren.


The journey of Lewis and Clark is one of the greatest of American stories.  The qualities of the members of that expedition: courage, determination, perseverance, superior judgment, and good fortune are ones that Americans identify as their own.

Meriwether Lewis and William Clark, who were the leaders of the expedition, also served as physicians for the Corps of Discovery, as the members of the group were called.  In September 1803, during the preparatory trip down the Ohio River, Lewis met with a physician, Dr. Ewing Patterson, who expressed a desire to go along on the expedition.  Lewis agreed to take him provided that he could ready by 3 PM the following day.  When Dr. Patterson did not appear at the appointed time, Lewis proceeded down the river without him.  In retrospect, it was perhaps fortunate that Dr. Patterson did not make the appointment, since he very likely was an alcoholic and would have been a detriment rather than a help to the success of the expedition.  Lewis and Clark were legally free to practice medicine, since there was no licensure of physicians at that time.

Lewis was born near Charlottesville Virginia in 1774.  His father, who was a Lieutenant in the Continental Army, drowned when Meriwether Lewis was five years old. It was from his mother, Lucy Meriwether Lewis Marks, who used plants found in that area of Virginia to treat relatives and neighbors, that he learned about the medicinal used of herbs.  At the age of 10, he moved with his family to the wilderness of northeastern Georgia, where he learned frontier skills.  About three years later, Lewis returned to Virginia for private tutoring.  At the age of 18, he took over the management of the family plantation.  Having become unhappy with the monotony of life there, Lewis joined the Virginia militia in 1794.  Later, he also served in the army, at one point under William Clark.  In 1801, he became the private secretary of President Thomas Jefferson, and thus had access to Jefferson’s library and intellect.  In the summer or fall of 1802 Jefferson appointed Lewis to command an expedition to the Pacific. Prior to the expedition, Jefferson sent Lewis to Dr. Benjamin Rush, who was one of the preeminent physicians of that day.  Dr. Rush was a signer of the Declaration of Independence and is known as the Father of American Psychiatry because of his advocacy for the humane treatment of the mentally ill and alcoholics.  Many cases of scurvy and smallpox were prevented in the Continental Army by his recommendation of citrus fruits and inoculation.  In common with other physicians of his day, Rush, however, had no correct understanding of the causes of diseases.  His primary treatments for all diseases were bleeding, purging, and sweating to deplete the body of “morbid” elements.

Clark was born in tidewater Virginia in 1770, a younger brother of the Revolutionary War hero, General George Rogers Clark. As a teenager, William Clark moved with his family to Kentucky. Having no formal education, he enlisted in the Kentucky militia at age 19. Later he served in the regular army as a Lieutenant.  During his military career, Clark participated in three Indian campaigns, including the Battle of Fallen Timbers as well as traveling extensively on the Ohio and Wabash Rivers.  He, along with other frontiersmen and military officers of that time, knew how to set a broken bone, incise and drain an abscess, and remove an imbedded arrow. By April 1793, Clark was already practicing frontier medicine.  He wrote in his diary that he had treated a sick man by bleeding him and causing him to sweat. In 1796, Clark resigned his commission to tend to family business.  He spent much of his time trying to clear the debts of his brother George, who had become an alcoholic.  When his father died in 1799, he inherited over 3000 acres, 23 slaves, and the family house and mill. On July 17, 1803, Clark received a letter from Lewis informing him of the upcoming expedition to the West and offering him the position of co-commander. Clark eagerly accepted.

After a period of preparation, recruitment, and training, the expedition departed from St. Charles, just up the Missouri River from St. Louis, on May 22, 1804. By October, they had reached the Mandan Villages in what is now North Dakota.  After spending the winter there, the Corps of Discovery departed in April 1805.  This group now was comprised of 28 soldiers including the captains, Clark’s servant York, Interpreter George Drouillard, Interpreter Toussaint Charbonneau, his wife Sacagawea and infant son Jean Baptise, as well as Lewis’ dog Seaman. They journeyed along the Missouri River into present day Montana through the White Cliffs area to the Great Falls.  After a difficult portage, the group continued up the river, through the “Gates of the Mountains” to the three forks area, where the Missouri split into three smaller rivers, which they named the Jefferson, the Madison, and the Gallatin.  The main party continued up the Jefferson, while a smaller party scouted the countryside to the west, where they made contact with the Shoshone Indians. The entire group then traveled further west to Lemhi Pass, where instead of the expected single mountain range, the view was of a series of mountain ranges as far as the eye could see.  Going over the continental divide into present day Idaho, the expedition was able to obtain horses from the Shoshones for their trip over the mountains.  The Corps then went north again up through western Montana, where they obtained additional horses from the Salish Indians, and then west across Lolo Pass into the Bitterroot Mountains.  After an extremely arduous trip over those mountains, the group reached the homeland of the Nez Perce.  Following a period of recuperation, the Corps reached the Clearwater River, which then joined the Snake River, which in turn flowed into the Columbia River.  On November 7, 1805, the mouth of the Columbia River and the Pacific Ocean were seen for the first time.  The very wet and dreary winter of 1805-1806 was spent at Fort Clatsop south of the Columbia.  Then on March 23, 1806 the expedition began the return trip.  After spending some time with the Nez Perce, the Corps crossed the Bitterroots.  After going across Lolo Pass, the group again camped at Travelers’ Rest.  The Corps then split with Lewis taking a part of the group east to the Missouri River and Clark taking most of the remainder south to the Yellowstone River and following it until it joined the Missouri.  In late September 1806 the reunited group arrived back in St. Louis.

The drugs and medical equipment purchased by Lewis corresponded to the medical treatments of that day.  For $90.69, he was able to buy a variety of lancets, syringes, and forceps, as well as a large number of medications, many of which were laxatives, emetics, or diaphoretics.  Fifty dozen of “Dr. Rush’s Thunderclappers”, a potent laxative were part of the purchase.  There were, however, at least two drugs which were effective and, in more purified forms, are still in use today.  Fifteen pounds of powered Peruvian bark was taken on the trip for the treatment of fevers.  Later in the nineteenth century this bark from the cinchona tree was found to contain quinine, which proved to be effective against malaria.  Since malaria was endemic in the Ohio and lower Mississippi and Missouri River valleys at that time, it is likely that some of the fevers treated on the expedition were indeed malaria.  Opium and laudanum, a tincture of opium, to relieve pain were also a part of the expedition’s formulary.

Smallpox was prevalent at the time of the expedition.  In Europe, it had been known since the early 18th century that a procedure known as inoculation could prevent the disease.  This procedure involved placing fluid from a pustle from a patient with smallpox into an incision or puncture wound, usually in the arm of the person to be inoculated.  Initially the mortality was high, but with refinement of the technique, the mortality from this procedure dropped to about one in 500.  In the late eighteenth century, an English physician, Edward Jenner, noted that milkmaids who contracted cowpox from the udders of infected cows never developed smallpox.  This led to his famous 1796 experiment in which he initially infected an eight year-old boy with cowpox and then several months later inoculated him with pus from another child with smallpox.  Immunity to smallpox was proven, when the vaccinated boy did not develop the disease.  Thomas Jefferson became aware of Jenner’s work and obtained a supply of the cowpox vaccine (“kinepox”), with which he vaccinated between seventy and eighty members of his family.  Jefferson instructed Lewis to carry some of the kinepox to use for vaccination of Indians.  It is likely that Lewis attempted vaccination of several Indians probably in Pittsburgh, at the start of his trip down the Ohio River, but the vaccine was ineffective, since there were apparently no “takes”. A request for another supply of vaccine was never acted upon. The devastating effects of previous epidemics of smallpox on the Indians were noted as the expedition traveled up the Missouri River in 1804.  It was not unusual to find that entire villages had been wiped out by the disease.

Only one man died during the course of the expedition.  In August 1804, 21 year-old Sgt. Charles Floyd developed acute abdominal pain.  It is not known what treatment he received, but it is likely that he was bled and that laxatives and emetics were given.  He died on August 20, 1804, the first United States soldier to die west of the Mississippi River, and was buried near present day Sioux City, Iowa.  Many medical historians believe that Floyd most likely died of peritonitis due to a perforated appendix, but others have suggested additional possibilities.  In any case, it is unlikely that any medical treatment available at that time would have been successful in saving Floyd’s life.

There were a number of medical problems during the winter of 1804-5, which the expedition spent at Fort Mandan in present day North Dakota.  On November 29, Sergeant Nathaniel Pryor suffered a dislocation of the right shoulder while taking down the mast of the keelboat.  The type of manipulation that was employed to reduce the dislocation was not described, but Clark did note that four attempts were required to reduce the shoulder. We also don’t know whether opium or laudanum was used to relax the shoulder musculature, but manipulation must have been difficult without some form of relaxation.  In January 1805, the weather became bitterly cold, with a temperature of 40 below zero having been recorded on one occasion.  A Mandan boy of about 13 was brought to the captains with frostbite involving his feet.  About two weeks later, Lewis again saw the boy and according to Clark “took off the toes of one foot”.  Later Clark wrote that he “sawed off” the boy’s toes.  Again the details of these treatments were not recorded, but it is likely that at least necrotic tissue was debrided.  The expedition’s medical kit did not contain a surgical saw, and amputation might have been beyond the captains’ capability. In any case, the boy was reported to have recovered.

It was during this winter at Fort Mandan that venereal disease was first noted.  In September 1804, a chief of the Brule Sioux had offered Lewis and Clark two young women for a sexual liaison, but the captains refused the offer.   In October, the expedition was in the land of the Arikaras, whose custom was to offer their women to visitors as a matter of hospitality.  York, Clark’s very large strong black slave had a particular allure. One of the Indian braves offered his wife to York and stood guard outside his house as the transfer of York’s “magic” took place. Early in 1805, the Mandans organized a Buffalo dance, a traditional ritual thought to ensure an adequate supply of buffalo.  Clark described the buffalo dance: “a Buffalow Dance for 3 night passes (past) in the 1st Village, a curious Custom  the old men arrange themselves in a circle & after smoke[ing] a pipe which is handed them by a young man, Dress[ed] up for the purpose,   the young men who have their wives back of the Circle go [each] to one of the old men with a whining tone and request to take his wife (who presents [herself] necked except a robe)  and – (or Sleep with her)   the Girl then takes the Old man (who verry often can scarcely walk) and leades him to a convenient place for the business, after which they return to the lodge; if the Old Man (or a white man) returns to the lodge without gratifying the Man & his wife, he offers him again and again; it is often the Case that after the second time without Kissing the Husband throws a new robe over the old man etc. and begs him not to dispise him & his wife   (We Sent a man to this Medisan Dance last night, they gave him 4 girls)   all this to cause the buffalow to Come near so that they may Kill them”.  Thus, there were multiple opportunities for the men of the expedition to become infected.

Many, but not all, historians believe that syphilis originated in the New World and was brought to Europe by sailors on the voyages of Columbus and other explorers.  In any case, many of the Indian tribes encountered by the expedition were infected with that disease. Until the mid -1850’s gonorrhea and syphilis were thought to be manifestations of the same disease process, although they were treated differently.  On the expedition, gonorrhea was treated by penile irrigations of sugar of lead and by oral copaiba. Syphilis was treated with mercury ointment for the local lesion. Oral mercury was used for the systemic manifestations of the disease and was titrated to the point of salivation.  The captains had both calomel (mercurous chloride) and the mercury containing Dr. Rush’s pills available for this purpose; we do not know which they used. Exactly how effective mercury was for the treatment of syphilis has never been clear, but it remained the treatment of choice until Salvarsan, an arsenic compound, was developed in the early twentieth century.  Significant amounts of mercury in what was thought to be the latrine trench were discovered in 2002 at Travelers’ Rest near Lolo Pass in Montana where the expedition stopped both in 1805 & 1806.

In mid June 1805, while the expedition was ascending the Missouri in northern Montana, Sacagawea became ill with abdominal pain, vomiting, and fever.  Clark bled her, gave her cathartics, and applied a poultice of powdered Peruvian bark to her lower abdomen.  She did not improve and when Lewis returned a few days later, Clark turned her care over to him.  By that time, Sacagawea’s pulse was rapid and irregular and she had twitching of her muscles.  She must have been dehydrated and likely had an electrolyte disturbance.  Lewis gave her water from a nearby spring as well as bark and laudanum.  Modern analysis of water from a spring within that area reveals it to contain significant amounts of sodium, potassium, and calcium.  Thus, the spring water that Sacagawea drank may well have corrected her dehydration and electrolyte abnormality and contributed to her eventual complete recovery. Her recovery was fortunate for the future success of the expedition.  Her interaction with the Shoshones, from whom she had been abducted as a child, was key in obtaining horses, without which the expedition would have not been able to continue. Her son, then only four months old, would likely have died had Sacagawea not recovered. Finally, as the only woman traveling with a band of soldiers, she lent an aura of peaceful intentions to the expedition.

As the expedition came to an area east of present day Helena, Montana, they encountered problems with painful feet.  On July 19, 1805, Lewis wrote: “the latter part of the evening their rout lay over a hilly and mountainous country covered with sharp fragments of flint which cut and bruised their feet excessively; nor wer the prickly pear of the leveler part of the rout much less painfull; they now become so abundant in the open uplands that it is impossible to avoid them and their thorns are so keen and stif that they pearce a double thickness of dressed deers skin with ease.  Cap C. informed me that he extracted 17 of these bryers from his feet this evening after he encamped by the light of the fire.  I have guarded or reather fortifyed my feet against them by soaling my mockersons with the hide of the buffaloe in parchment [i.e., hard-dried].”  The following night Lewis wrote that the prickly pears were so abundant that the men could scarcely find room to lie down.  That valley is now known as Prickly Pear Valley and the creek running through it as Prickly Pear Creek.  On the 22nd Clark wrote: “I opened the bruses and blisters of my feet which caused them to be painful”.  He would have been better off if he had punctured the blisters and allowed the underlying skin to heal. Mosquitoes and gnats were also bothersome.  Lewis on July 24: “our trio of pests are the Musquetoes eye knats and prickley pears, equal to any three curses that ever poor Egypt laiboured under”.

The trails over the Bitterroot Mountains were steep and snow covered.  When the expedition arrived at the land of the Nez Perce in late September 1805, they were exhausted and hungry and many suffered from boils and diarrhea.  The Nez Perce could have easily killed all the white men and taken their guns, ammunition, and goods, which would have made those Indians the richest and best armed of any tribe west of the Mississippi. Fortunately, one of the Indian women who had been treated well by a white man in the past dissuaded her people from taking action.  After gorging themselves on the dried fish, roots, and berries which they bought from the Indians, the men of the expedition became ill with cramping abdominal pain and dysentery.  The illness may have been due to change in diet, but an infectious cause of the gastroenteritis seems more likely.  Treatment with Dr. Rush’s pills very likely made the problem worse at least initially.  Recovery was slow, but in about two weeks the members of the Corps of Discovery were able to leave the Nez Perce and begin their river journey to the Pacific Ocean.

The winter of 1805-6 spent at Fort Clatsop was cold and wet.  During the three and half months that the Corps spent there, rain was nearly constant and the sun was seen on only six days.  As might have been expected from the close quarters, the monotonous diet, and the climate, respiratory infections were common.  A few of the men became quite ill, possibly with pneumonia.  Treatments, as noted previously, consisted of Rush’s pills, Peruvian bark, and laudanum.   Many of the men consorted with the Clatsop women, resulting in more mercury treatments. Private William Bratton developed severe back pain, which did not respond to treatment.  Fortunately by the time the Corps left Fort Clatsop in late March 1806, all had markedly improved except for Bratton, who continued to have intermittent pain.

It was during the trip up the Columbia River system that Clark became a well regarded physician by the Indians of that area.  The Corps spent several days in late April 1806 with the Walla Walla Indians.  An Indian with a broken forearm was brought to Clark loosely bound with leather.  Clark wrote: “I dressed the arm broken short above the wrist & supported it with broad sticks to keep it in place, put [it] in a sling and furnished him with some lint bandages &c. to Dress it in the future”.  Clark mentions treating another patient with a broken arm, another with “inward fever”, others with “pains across their loins”, colds, and sore knees.  Eye complaints were common among the Indians, which Clark attributed to the fine sands blown by the wind.  In fact, infectious conjunctivitis, gonorrhea, or trachoma may have been more common causes.  In any case, “eye water”, containing zinc sulfate and lead acetate became the medication most commonly dispensed by Clark.  It probably relieved the eye symptoms for a few days, but had no long term benefits, although zinc does have a mild antibacterial effect.  On some days as many as forty Indians with sore eyes lined up to be treated. During his stay with the Walla Walla Indians, Clark received a horse and a canoe for his services.

The expedition moved on the to the lands of the Nez Perce, where they spent most of May and the first half of June 1806, waiting for the snow in the mountains ahead of them to melt.  Again Clark set up a clinic for medical treatment of the Indians.  By this time, the expedition’s trade goods were depleted and payment for medical services was important in obtaining food, horses, and dogs, which later could be eaten if necessary.  The wife of a Chief was brought to Clark with an abscess in her back.  Clark incised the abscess, drained the pus, packed the cavity with cloth, and applied an ointment. A Chief who had been unable to move his arms or legs for several years was brought for treatment. There had been no history of injury and no complaint of pain.  Despite this “paralysis”, it was noted that there was no muscle atrophy and that in other respects the Indian appeared to be in good health.  A change in diet and cold baths were advised, and medication having laxative, diuretic, and sweat inducing properties was dispensed.  The Chief did not improve on this regimen.  In the meantime, Private William Bratton was still complaining of back pain.  Private John Shields recalled seeing patients with back pain having been helped by sweat baths. Bratton indicated that he wished to try that treatment.  A pit four feet deep and three feet in diameter was dug.  A fire was built at the base of the pit and allowed to burn until the ground in the pit was warmed.  The embers were removed and a naked Bratton entered the pit and sat on a wooden seat.  The hole was covered and water was sprinkled into the pit creating steam.  Bratton sat in this steam bath for twenty minutes, after which he was plunged into cold water.  The same procedure was repeated twice more with Bratton staying in the pit for twenty minutes again and then for forty minutes for the final treatment.  The following day, the pain was nearly gone and Bratton felt better than he had in months.  Bratton may have had a herniated lumbar disk with muscle spasms.  The heat probably relaxed the muscle spasms and could have reduced swelling around the disk.  Perhaps Bratton had degenerative arthritis which was relieved symptomatically or perhaps he was malingering.  Having heard of Bratton’s improvement, the Chief asked for the same treatment.  The pit was again heated, but had to be enlarged to accommodate the Indian. While in the pit, the Chief had increased pain requiring laudanum.  In the following days, however, there was marked improvement.  After a second treatment, arm movements were almost back to normal and there was improvement in the legs as well. The reason for the Chief’s improvement is difficult to understand.  A psychosomatic cause is perhaps the best explanation.

The expedition was finally able to leave the Nez Perce on June 10, 1806.  By early July, the Corps had reached Traveler’s Rest again.  There the group split with Lewis and the main party taking an easterly route to the Missouri River and Clark with a smaller group going south, eventually proceeding down the Yellowstone River.  On August 11, while setting out on the Missouri River to determine the latitude of the river’s northern most point, Lewis spotted a herd of elk.  Having arrived too late to take the sun’s meridian, he decided to go hunting, taking boatman and fiddler Private Pierre Cruzatte with him. Lewis killed one elk and Cruzatte wounded another.  They then separated, going through a grove of willows, in an attempt to find the wounded elk.  Lewis wrote: “ I was in the act of firing on the Elk a second time when a ball struck my left thye about an inch below my hip joint, missing the bone it passed through the left thye and cut the thickness of the bullet across the hinder part of the right thye”.  The bullet went all way the through, lodging in Lewis’s breeches.  Cruzatte who was blind in one eye and had poor vision in the other had mistaken the leather clad Lewis for an elk.  Lewis was in severe pain and had considerable bleeding, but eventually was able to make it back in the pirogue, where he dressed the wounds himself with “tents of patent lint”.  With Lewis lying on his stomach, the pirogue proceeded down the river and caught up with Clark’s party the following day.  Clark cleaned and redressed the wounds. The tent bandage which he used pointed out and down and was designed to drain the pus. Despite the unsanitary conditions, there was no evidence of serious infection and by the completion of the journey, Lewis had completely recovered.

On September 23, 1806, the Corps of Discovery reached St. Louis, thereby completing their amazing journey.  Remarkably, only one man had died.  While this excellent outcome was due primarily to the youth and superb physical condition of the members of the expedition as well as to good luck, one must also give Lewis and Clark high marks for their service as physicians. With the medical knowledge and treatments available to them, they had done a remarkable job.



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Thomas P. Lowry, Venereal Disease and the Lewis and Clark Expedition, (Lincoln,

Nebraska: University of Nebraska Press, 2004).

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Arizona: Patrice Press, 1996).

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Medical Journal:

Brian Vastag, Medicine on the Lewis and Clark Trail, JAMA 289: 1227-1230, March 12,