'Specimene of the Stone'

masthead saying 'We Proceeded On'
Reprinted from We Proceeded On1

The Fate of Lewis and Clark's Mineralogical Specimens

Eagle Creek Morning

Upper Missouri River Breaks National Monument

White cliffs behind the Missouri River

Photo by Kris Townsend, © May 22, 2016.

The Expedition camped at this location on 31 May 1805. According to Sergeant Ordway, "Capt. Lewis walked on shore." Perhaps Lewis descended here and crossed Eagle Creek which flows right-to-left through the lower half of this photo. Camp that night was likely in the stand of Cottonwood just across the creek.

Eagle Creek Evening

White cliffs behind a Missouri River cottonwood grove

Photo by Kris Townsend, © May 21, 2016.

View: looking across the 31 May 1805 campsite to white cliffs to the right of the Missouri River.

—Ed. Kris Townsend

In the late afternoon of May 31, 1805, after another long and arduous day of struggling against the unrelenting current of the Missouri River, Meriwether Lewis, William Clark, and the rest of the Corps of Discovery made camp at Stonewall (now Eagle) Creek in present-day Montana. The laborious work of hauling the canoes and pirogues upstream may have been achingly monotonous and familiar to the explorers, but the route they traveled this day had been a singular revelation. They were passing through a series of remarkable freestanding stone walls and brilliantly white sandstone cliffs, the inspiration for Lewis's famed journal passage about "seens of visionary inchantment" and "most romantic appearance" describing the White Cliffs region of the Missouri.2 Yet the captains' work on this memorable day was not over by any means.

Intrigued by the extraordinary freestanding stone walls that rose on each side of the river, Lewis and Clark summoned the energy to have a closer look at these unique geological features, and not just because they desired to include more detail in their journals. Lewis and Clark were acutely aware that observations of the "mineral productions of every kind" were an essential part of the scientific mission that Thomas Jefferson had outlined for them two years before, but the captains had another objective in mind in the waning light of this late afternoon. As Clark wrote, "both Capt Lewis and My self walked on Shore this evening and examined those walls minutely and preserved a Specimine of the Stone."3

A Multitude of Mineralogical Specimens

Although not nearly as celebrated as their botanical and zoological work, Lewis and Clark collected a multitude of mineralogical specimens throughout the expedition. There are numerous places in the journals where it's obvious the captains are collecting rock and mineral specimens. The best known incident took place on August 22, 1804, when Lewis, attempting to assay a specimen, was overcome by what Clark assumed were fumes of arsenic or cobalt.4

Lewis's incapacitation may have dampened the captains' zeal for conducting such experiments, but it did nothing to deter them from continuing their collecting activities. Perhaps realizing their own limitations in the proper identification of rocks and minerals—still a very inexact science in the early 1800s—Lewis and Clark made the wise choice of dealing with mineralogy in the same way they did botany and zoology, by diligently collecting representative samples for shipment back East, where experts could make the proper descriptions and chemical analyses.

Three Separate Collections

Lewis and Clark appear to have assembled at least three separate collections of rock, mineral, and fossil specimens during the expedition, not counting the special shipment of mammoth bones and teeth recovered from Big Bone Lick, Kentucky, that Lewis sent to Thomas Jefferson in the fall of 1803.

The following discussion seeks to unravel the complicated collection history and ultimate fate of the captains' mineral specimens. It addresses when each shipment of specimens arrived in the East, determining who received and described them, evaluating the accuracy of these descriptions, hypothesizing how the rocks and minerals fell into the hands of a private collector before transfer to the Academy of Natural Sciences (A.N.S.) in Philadelphia, reviewing which specimens survive to the present day, and assessing whether the captains' mineralogical collection played a role in influencing scientific thought and the advancement of geology and mineralogy in the early nineteenth century.

  • 1. John W. Jengo, "'Specimine of the Stone': The Fate of Lewis and Clark's Mineralogical Specimens," We Proceeded On, August 2005, Volume 31, No. 3, the quarterly journal of the Lewis and Clark Trail Heritage Foundation. Editorial additions include page titles, side headings, and graphics to assist the web-based reader. The original format is provided at http://lewisandclark.org/wpo/pdf/vol31no3.pdf#page=18.
  • 2. Gary E. Moulton, ed., The Journals of the Lewis and Clark Expedition, 13 volumes (Lincoln: University of Nebraska Press, 1983–2001), Vol. 4, 225–226. All quotations or references to journal entries in the ensuing text are from Moulton, by date, unless otherwise indicated.
  • 3. Ibid., 232.
  • 4. Ibid., Vol. 2, 500–501. Clark describes this incident in both his field notebook and journal. In the first he says that Lewis "was near being Poisened by the Smell in pounding this Substance I belv to be arsenic or Cabalt." In the second he indicates that Lewis also tasted the substance.