Secrets Uncovered at Graham Cave State Park

Archaeologists once conducted extensive excavations of an unusual sandstone cave to uncover evidence of early human activity in Missouri. Today, Graham Cave State Park protects the landforms that supported these ancient ancestors.

In the hills above the Loutre River in Montgomery County, a few miles north of the Loutre’s confluence with the Missouri River, is an outcrop with a large cave created at the contact zone between St. Peter sandstone and Jefferson City dolomite. Caves in dolomite or limestone are common enough, but a sandstone cave is less common. What happened here is that the dolomite below was more soluble and slowly dissolved away, leaving a cavity under the sandstone. Some of the sandstone crumbled and collapsed into the cavity, enlarging it, and leaving an arch-like entrance 120-feet wide and 16-feet high. Originally the cave extended about a hundred feet into the hill. An accumulation of debris and dust over the years then filled the lower part of the cave with about seven feet of deposit. 

What is noteworthy, though, is not so much the cave, rare as it is, as what has been found in the debris on its floor. This cave, like others so favorably situated, was an admirable shelter for animals and people through the years—just how many years would one day be discovered. 

The cave was a mile north of the early nineteenth-century settlement of Loutre Lick, now known as Mineola, then noted for its mineral springs with reputed medicinal powers. This “lick” was owned by sons of Daniel Boone, whose claims dated from 1802 during the Spanish colonial era. The Boone’s Lick Trail, the trail they took west from St. Charles, went right past the Loutre Lick and on to the more famous Boone’s Lick salt works, which they also operated. 

Dr. Robert Graham, a Scotsman who came to Missouri from Kentucky in the wave of migration that followed the War of 1812, settled in the area in 1816 and purchased from Daniel Morgan Boone a portion of his rich bottomland along the Loutre River. Loutre—French for otter—is the name by which the river was known as early as the French explorer Étienne de Veniard sieur de Bourgmond’s 1723 trip up the Missouri River to the mouth of the Grand River, where he would found Fort Orleans. 

The land in this area declines rapidly in agricultural potential as it leaves the river, climbing to the rugged and rocky escarpment that rims the edges of the valley—so much so that Graham did not pursue ownership of the ridge-top quarter-section that contained the cave until 1847, when it was still available directly from the U.S. government. Graham raised black Angus cattle brought from Kentucky and is said to have mined saltpeter from the cave to sell to St. Louis gunpowder factories. 

Graham’s son, D. F. Graham, became interested in archaeology, digging numerous Indian mounds in the vicinity and even making a test excavation in the cave. His collection of artifacts grew so large that his wife made him build another structure, the “relic house,” to store them. After his death, his son Benjamin, who had studied at the University of Missouri, offered the artifact collection to the university. Professors Jesse E. Wrench and J. Brewton Berry, who were interested in archaeology, visited the cave in 1930 to assess its potential, but did little digging. This was before the formation of the Missouri Archaeological Society or any formal archaeological study at the university. Benjamin’s daughter Frances married Ward Darnell. After World War II, archaeologists were much better organized when they learned Darnell was bulldozing the debris in the cave. Fortunately, they persuaded him to hold off. 

From 1949 through about 1955, archaeologists Wilfred Logan and Carl Chapman of the University of Missouri and the Missouri Archaeological Society conducted extensive excavations in the cave. The results were staggering. Within a deep portion of the deposits, they found evidence of the oldest known humans in Missouri up to that time. These discoveries were being made just as the new carbon-14 technology for dating organic material such as bone or wood was substantially revising archaeologists’ notions of when early people had arrived on the continent. It had once been thought that they had arrived less than three thousand years ago, but discoveries in New Mexico were forcing scientists to push their estimates backward. The hard evidence came with radiocarbon dating at places like Graham Cave. 

The lowest deposits in the cave belonged to the Dalton Period— named for Missouri Supreme Court Judge S. P. Dalton, himself an amateur archaeologist who first studied the distinctive projectile point that characterized the period. During that time, native people were adjusting to the rapidly changing climate, vegetation, and animal life after the retreat of the glaciers. Another adjustment in thinking was involved here because before carbon-14 dating became available, scientists thought the last glaciers had retreated perhaps as much as twenty-five thousand years ago; now they were finding evidence of the last, or Wisconsin, glaciation still in Wisconsin as recently as ten thousand years ago, at the same time as the early occupation of Graham Cave. 

The extremely significant discoveries at Graham Cave, including not only the oldest materials but also the remarkable evidence of ways of life and adaptations to the environment over ten millennia, were recognized in November 1961 when Graham Cave became the first archaeological site in the nation to be designated a National Historic Landmark. Frances Graham Darnell, great-granddaughter of Dr. Robert Graham, took pride in the discoveries made on her land and donated 237 acres—land that had been in her family for nearly a century and a half—to the state in 1964. This was the core of what is today Graham Cave State Park. 

From 1967 to 1968, further excavation was conducted by archaeologist Walter Klippel, in part to test whether changes in the environment during the Archaic period—ten thousand to three thousand years ago—were reflected in cultural material. Analysis of soil deposits in the cave indicated that this area underwent rapid warming from the cool glacial period after about eight thousand years ago, and that until about five thousand years ago, this area shared a warm dry period that allowed the eastward extension of prairie grasses across northern Missouri, Iowa, and Illinois in what has become known as the Prairie Peninsula. During this time, faunal remains in the cave showed a gradual but marked change from forest mammals to species that prefer an edge habitat, reflecting a change from forest to mixed prairie and woodland. Study of the types of stone tools, however, suggested that the cave was used for generally the same purposes through time. More than 99 percent of the stone used for the tools was locally available, though the manner of manufacture changed over time, suggesting that people may have adapted in place to their changing environment rather than dying or moving out and differ ent cultural groups migrating in.

For interpretive purposes, the 1960s excavations were left open behind a protective barrier, instead of being backfilled. Because of this, they’ve been degraded by burrowing animals and erosion, so park managers have recently begun a stabilization program. These were probably the best-preserved deposits from this time in the state, and undisturbed portions of the site being banked for future excavation may still retain that distinction. We likely have more to learn from Graham Cave.

Today, the 386-acre park protects not only the cave that sheltered early inhabitants but also vestiges of the landscape that supported them. A rich bottomland forest along the Loutre River changes into oak woodlands upslope, and then into rocky, sun-drenched glades. Glades within the park are found on sandstone, several limestones, and dolomite bedrock that outcrop here at this northern edge of the Ozark Border. The glades on each type of rock produce their own characteristic plant and animal life. Unique to the park system are isolated carpets of a moss-like fern called spikemoss, which grows on dry, exposed sandstone glades.

The importance of these remnant glades—among the best glades in Missouri—has led to the designation of an 80-acre tract as the Graham Cave Glades Natural Area. Park managers have restored not only the glades but also the open woodlands around them by removing the young thickets of eastern red cedar and using prescribed burns to keep them open for sun-loving plants that thrived here for millennia when wildfires were more prevalent. 

A walk through the natural area passes by some of the park’s glades. Another short trail leads from the popular campground to the Loutre River and a boat-launch area, and a trail from the lower picnic area to the cave passes a shelter with exhibits about the park’s archaeology and natural history. The visitor center displays artifacts from the excavations, and a diorama of the cave area tells the story of both the natives and the landscape they inhabited for nearly ten thousand years. 

GRAHAM CAVE STATE PARK • 217 HIGHWAY TT, DANVILLE 

Feature photo courtesy of Ben Nickelson

Purchase the Missouri State Parks and Historic Site book here.