Franktown Cave is located 25 miles south of
Denver
Denver () is a consolidated city and county, the capital, and most populous city of the U.S. state of Colorado. Its population was 715,522 at the 2020 census, a 19.22% increase since 2010. It is the 19th-most populous city in the Unit ...
,
Colorado
Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of t ...
on the north edge of the Palmer Divide. It is the largest rock shelter documented on the
Palmer Divide
Named after Colorado Springs founder William Jackson Palmer, the Palmer Divide is a caprock escarpment style ridge in central Colorado that separates the Arkansas River basin from the South Platte basin. It extends from the Front Range of the Rock ...
, which contains artifacts from many prehistoric cultures. Prehistoric
hunter-gatherer
A traditional hunter-gatherer or forager is a human living an ancestrally derived lifestyle in which most or all food is obtained by foraging, that is, by gathering food from local sources, especially edible wild plants but also insects, fungi, ...
s occupied Franktown Cave intermittently for 8000 years beginning about 6400 B.C. The site held remarkable lithic and ceramic artifacts, but it is better known for its perishable artifacts, including animal hides, wood, fiber and corn. Material goods were produced for their comfort, task-simplification and religious celebration. There is evidence of the site being a campsite or dwelling as recent as AD 1725.
Geography
Franktown Cave is a
rock shelter
A rock shelter (also rockhouse, crepuscular cave, bluff shelter, or abri) is a shallow cave-like opening at the base of a bluff or cliff. In contrast to solutional caves (karst), which are often many miles long, rock shelters are almost alway ...
above Willow Creek, a tributary of
Cherry Creek that flows into the
South Platte River
The South Platte River is one of the two principal tributaries of the Platte River. Flowing through the U.S. states of Colorado and Nebraska, it is itself a major river of the American Midwestern United States, Midwest and the American Sout ...
at
Denver, Colorado
Denver () is a consolidated city and county, the capital, and most populous city of the U.S. state of Colorado. Its population was 715,522 at the 2020 census, a 19.22% increase since 2010. It is the 19th-most populous city in the Unit ...
, 25 miles to the north. It is more than in
elevation
The elevation of a geographic location is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface (see Geodetic datum § Vert ...
.
[
Situated on ]Palmer Divide
Named after Colorado Springs founder William Jackson Palmer, the Palmer Divide is a caprock escarpment style ridge in central Colorado that separates the Arkansas River basin from the South Platte basin. It extends from the Front Range of the Rock ...
, which separates the South Platte River
The South Platte River is one of the two principal tributaries of the Platte River. Flowing through the U.S. states of Colorado and Nebraska, it is itself a major river of the American Midwestern United States, Midwest and the American Sout ...
basin from the Arkansas River
The Arkansas River is a major tributary of the Mississippi River. It generally flows to the east and southeast as it traverses the U.S. states of Colorado, Kansas, Oklahoma, and Arkansas. The river's source basin lies in the western United Stat ...
basin, Franktown Cave is its largest documented rock shelter in the area.[ Palmer Divide is an east–west ridge in central Colorado that runs ]perpendicular
In elementary geometry, two geometric objects are perpendicular if they intersect at a right angle (90 degrees or π/2 radians). The condition of perpendicularity may be represented graphically using the ''perpendicular symbol'', ⟂. It can ...
to the Rocky Mountains
The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...
between Denver and Colorado Springs and east to Limon, Colorado. Monument Hill, is the highest point of the divide at about .
The cave was created when water eroded the soft, water soluble layers of Dawson Arkose
Arkose () or arkosic sandstone is a detrital sedimentary rock, specifically a type of sandstone containing at least 25% feldspar.
Arkosic sand is sand that is similarly rich in feldspar, and thus the potential precursor of arkose.
Quartz is c ...
formation through seeps
A petroleum seep is a place where natural liquid or gaseous hydrocarbons escape to the earth's atmosphere and surface, normally under low pressure or flow. Seeps generally occur above either terrestrial or offshore petroleum accumulation stru ...
below a thick, hard shelf of Castle Rock Conglomerate
Conglomerate or conglomeration may refer to:
* Conglomerate (company)
* Conglomerate (geology)
* Conglomerate (mathematics)
In popular culture:
* The Conglomerate (American group), a production crew and musical group founded by Busta Rhymes
** Co ...
. The area provides two key raw materials that were used for tool-making:
* Microcrystalline
A microcrystalline material is a crystallized substance or rock that contains small crystals visible only through microscopic examination. There is little agreement on the range of crystal sizes that should be regarded as microcrystalline, but the ...
rock in white chalcedony, light yellow and caramel that was formed from petrified wood during the Paleocene
The Paleocene, ( ) or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), E ...
period. Projectile points and small biface
A hand axe (or handaxe or Acheulean hand axe) is a Prehistory, prehistoric stone tool with two faces that is the longest-used tool in human history, yet there is no academic consensus on what they were used for. It is made from stone, usually f ...
s were made from microcrystalline
A microcrystalline material is a crystallized substance or rock that contains small crystals visible only through microscopic examination. There is little agreement on the range of crystal sizes that should be regarded as microcrystalline, but the ...
rock.
* Wall Mountain
A wall is a structure and a surface that defines an area; carries a load; provides security, shelter, or soundproofing; or, is decorative. There are many kinds of walls, including:
* Walls in buildings that form a fundamental part of the super ...
tuff rhyolite from the Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...
age for flake tools.[
Near the rock shelter, spring-fed streams traverse a land of ]scrub oak Scrub oak is a common name for several species of small, shrubby oaks. It may refer to:
*the Chaparral plant community in California, or to one of the following species.
In California
*California scrub oak (''Quercus berberidifolia''), a widespr ...
, plains grassland
A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur natur ...
and open ponderosa pine forest
Ponderosa pine forest is a plant association and plant community dominated by ponderosa pine and found in western North America. It is found from the Rocky Mountains to the Pacific Coast Ranges in the Western United States and Western Canada. In t ...
.[
]
Physical Characteristics
Franktown Cave is the largest rockshelter documented in the Palmer Divide. The overhang is about wide, and measures between the dripline and the rear wall in the northern half of the shelter. This is where most of the excavations were placed and the majority of the artifacts were found. The shelter is naturally divided into a lower and upper shelter. The upper shelter is on the south side and the lower shelter is on the north side. Very little documented excavation has occurred in the upper shelter, because it has thin sediment cover over the bedrock and is periodically saturated with water. Very few artifacts have been found in the upper shelter.[
]
History
Prehistoric cultural periods of eastern Colorado are traditionally identified as: Paleo-Indians at the earliest, Archaic
Archaic is a period of time preceding a designated classical period, or something from an older period of time that is also not found or used currently:
*List of archaeological periods
**Archaic Sumerian language, spoken between 31st - 26th cent ...
, Ceramic
A ceramic is any of the various hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcelain ...
and Protohistoric phases.[Nelson.] Evidence of Franktown Cave habitation began with the early Archaic period about 6,400 BC and continued through each of the remaining cultural periods to AD 1725.[
]
Archaic periods
People of the Archaic period moved seasonally to gather wild plants and hunt game, such as deer, antelope and rabbits. Late in the Archaic period, about AD 200–500, corn was introduced into the diet and pottery was made for storing and carrying food.
The early, middle and late Archaic periods are all represented at the Franktown cave. The early period was marked by a nomadic hunter-gatherer
A traditional hunter-gatherer or forager is a human living an ancestrally derived lifestyle in which most or all food is obtained by foraging, that is, by gathering food from local sources, especially edible wild plants but also insects, fungi, ...
lifestyle in the mountains and foothills, adapted to smaller game and greater reliance on gathering wild plants for food than their Paleo-Indian ancestors. During this period new stone tools were created to process and prepare plants for meals. Gilmore submits that bison antiquus, the primary source of food for the Paleo-Indian, became extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
due to increasingly warm and arid climate changes of the Holocene Altithermal period warm period about 9,000 to 5,000 years ago To survive people adapted by hunting smaller game and gathering plants, seeds, and nuts.[
As of 2005, Franktown Cave is the only well documented rockshelter site to have evidence of middle Archaic occupation on the Palmer Divide. Based upon archaeological evidence, it appears that mountain people had longer transitional periods through the Archaic and Ceramic periods than those on the Plains. Franktown Cave residents who were adapted to the mountain culture, were also slow in integrating ]bow and arrow
The bow and arrow is a ranged weapon system consisting of an elastic launching device (bow) and long-shafted projectiles ( arrows). Humans used bows and arrows for hunting and aggression long before recorded history, and the practice was comm ...
technology and other advancements.[
]
Ceramic periods
The Early Ceramic, or Woodland, period began in the Plains about AD 0, distinguished by the introduction of the cordwrapped pottery and the bow and arrow
The bow and arrow is a ranged weapon system consisting of an elastic launching device (bow) and long-shafted projectiles ( arrows). Humans used bows and arrows for hunting and aggression long before recorded history, and the practice was comm ...
. People also began to live in small settlements.[
At Franktown, Early Ceramic artifacts include a pottery fragments, a fragment of a coiled basket similar to the earlier periods, and a small corner-notched point - which seems to indicate that the uptake of new technology was slower here than at some other sites during the Early Ceramic period.][
Artifacts from AD 780–1290, the middle Ceramic period, include small, distinctive side-notched projectile points, clothing, charcoal, potsherds, a sinew and twig net, and corn cobs. The sinew and twig net is similar to hoops used for several Native American nations' games. Franktown artifacts from the Archaic period reflect the influence of the southern Apishapa culture of the Arkansas basin and the Upper Republican plains people of the South Platte basin in northeastern Colorado and northwestern Kansas. The pottery has the conical shape of Plains Woodland pottery and the cord-markings and rims of Upper Republican pottery.][
Population size and mobility changed during the Archaic periods. The number of early Ceramic period sites increased, reflecting an increase in population. By the middle Ceramic phase, there was a marked decrease in the number of sites. People stayed in one place for shorter periods of time and were part of smaller and more mobile groups.][
]
Protohistory
The groups of people during this period became much more diverse, were more likely to settle in a location or a couple of locations, cultivate food, domesticate animals, make pottery and baskets, and perform ceremonial rituals.[Waldman, 14.] Artifacts from 1540 to 1860, the latest prehistoric period, include corn cobs, arrow points and what appear to be Dismal River Gray ceramic fragments. It is believed that the people of the Dismal River culture
The Dismal River culture refers to a set of cultural attributes first seen in the Dismal River area of Nebraska in the 1930s by archaeologists William Duncan Strong, Waldo Rudolph Wedel and A. T. Hill. Also known as Dismal River aspect and Dism ...
were Apache
The Apache () are a group of culturally related Native American tribes in the Southwestern United States, which include the Chiricahua, Jicarilla, Lipan, Mescalero, Mimbreño, Ndendahe (Bedonkohe or Mogollon and Nednhi or Carrizaleño an ...
Native Americans. While the Middle Ceramic period reflected a significant decrease in population, it appears as if there was an upswing in eastern Colorado population during the Protohistoric period.[
]
Archaeology
Rock shelter description
The rock shelter, sheltered from extreme precipitation and temperature extremes, faced east. It is the largest documented Palmer Divide rock shelter as of 2005, measuring wide by at its deepest point. At the front edge of the cave, large rocks provided a protecting barrier. There is a lower level on the southern portion of the cave and another several yards higher on the northern side. The southern portion of the cave was dry which preserved most of the excavated items. The upper level had a water seep and few artifacts were found there.[
]
Artifacts
More than 4000 artifacts were recovered from Franktown cave in the 1940s and 1950s. They can be divided into four categories. 2180 chipped stone artifacts were excavated. This includes projectile points and fragments. 234 groundstone artifacts were recovered, and 862 potsherds were recovered as well. Potsherds include cord marked and plain wares. 351 perishable artifacts were excavated. This includes fibers, animal hide, bones, and wood. 791 ecofacts were recovered as well.[ Ecofacts such as corn and other plant remains, as well as, animal remains, shells and wood. Perishable artifacts and ecofacts are almost completely unknown from sites in the Platte River Basin, and the quantity and variety of the artifacts found is unmatched in the northeastern part of the state.][
Examination of the ceramic vessels show that they were made of patches of clay which were then bonded and strengthened using a paddle and anvil technique. This technique is common on Plains sites. It was also found that some of the materials the pottery was made from were local materials. The analysis of the pottery reflects that there was a more intensive occupation of Franktown Cave at the end of the Early Ceramic and the beginning of the Middle Ceramic.][King.]
Research into the woven materials indicates technical affinities with peoples to the South and Southwest during the early to middle Archaic transition. Such woven materials include sandals. It was found that different types of sandals were made for the winter and the summer. A more complex sandal with straps meant to hold grass socks were used in the cooler months, while a lighter sandal was used in the warmer months.[
Hide used for the production of clothing were found in the faunal remains. There were a high number of bison bone and other large fauna. The presence of rodent bones, snares and rabbit hide robes suggests that small game was also important.][ Another perishable artifact found was a moccasin, which was worn from use. AMS dates on the moccasin suggest that it was discarded sometime between AD 980 and 1160.][ The lithic technology suggests extensive reliance on the locally available petrified wood, rhyolite, and quartzite. This pattern of heavy reliance on local raw materials holds to other sites in the Palmer Divide area.
Corn may have been significant to people living in Franktown Cave in different ways at different times. People first began using corn at Franktown Cave in the transition from the Early Ceramic to the Middle Ceramic era.][ During the Middle Ceramic the climate was wetter and milder, and the human population in the area was higher.
Excavations were conducted intermittently since the 1940s focused primarily on the southern, lower level of the cave. 4000 pre-historic items were found at the site, 2180 of which were chipped stone artifacts. The table below shows the artifacts found by cultural period and period of time, dated by Accelerator Mass Spectrometry (AMS) and ]Radiocarbon dating
Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon.
The method was dev ...
.[
Franktown Cave is similar to ]Trinchera Cave Archeological District
The Trinchera Cave Archeological District ( 5LA9555) is an archaeological site in Las Animas County, Colorado with artifacts primarily dating from 1000 BC to AD 1749, although there were some Archaic period artifacts found. The site was added t ...
and Chamber Cave, all of which showed significant evidence of residence, including a wealth of perishable items. The Trinchera and Chamber Cave sites are located south of Franktown Cave in the Arkansas River
The Arkansas River is a major tributary of the Mississippi River. It generally flows to the east and southeast as it traverses the U.S. states of Colorado, Kansas, Oklahoma, and Arkansas. The river's source basin lies in the western United Stat ...
basin and were influenced by the people of the southern Great Plains
The Great Plains (french: Grandes Plaines), sometimes simply "the Plains", is a broad expanse of flatland in North America. It is located west of the Mississippi River and east of the Rocky Mountains, much of it covered in prairie, steppe, an ...
.[
]
Artifact counts and description by category
The counts of artifacts by category are:[
]
Excavation and studies
Franktown Cave has been excavated for the past fifty years. Hugh O. Capp, Jr. Was the first to excavate Franktown Cave in 1942. He worked on the north end of the cave. He left the University of Denver with the artifacts in paper sacks, along with his report and all his sketches and photographs. Unfortunately, his report has never been found. Arnold Withers was next to excavate the cave. Withers first excavated in 1949 then again in 1952. The only remaining notes associated with these excavations are a map by Gilbert Wenger, which shows the locations of each “Stratitest” and the test pits, and a stratigraphic profile drawn by David Breternitz. Withers never wrote a report of his finds at Franktown Cave.[
Gerold “Tommy” Thompson was the next to excavate Franktown Cave in 1956 and 1957. He recorded a great deal about his excavation. Thompson recovered a sandal and cordage during his excavations. He analyzed the sandal and determined that there were at least two types of sandals. Winter sandals which had more complex straps and a grass sock, and a summer sandal with simpler straps and no grass sock. Charles W. Manz, analyzed 500 pieces of lithic debitage, waste flakes from the manufacture of stone tools in the Franktown Cave collection in 1973. He found that 40% of the debitage showed evidence of breakage after deposition and bag wear. This suggests breakage after collection due to rough or improper handling. His study indicated that people at Franktown Cave mainly used expedient tools from the locally available raw materials.][
Sarah M. Nelson and Sarah Studenmund collaborated on a paper and found that the pottery from Franktown cave can all be considered a single type. They found no statistical difference between the cord-marked and smooth pottery, except for the presence or absence of the marks.][
The site has also been subject to excavations before the 1940s by local Boy Scouts and has been subject to looting over time.][
]
Historical significance
Franktown Cave was added to the National Register of Historic Places
The National Register of Historic Places (NRHP) is the United States federal government's official list of districts, sites, buildings, structures and objects deemed worthy of preservation for their historical significance or "great artistic v ...
in 2006.
See also
*
* Cedar Point Village - archaeological site in southwestern Colorado also having Dismal River culture artifacts
* Cherry Creek Rockshelter
* List of prehistoric sites in Colorado
Notes
References
Bibliography
* Cassells, E. Steve. (1997) 983''The Archaeology of Colorado.'' Boulder: Johnson Press. .
* Gibbon, Guy E.; Ames, Kenneth M
''Archaeology of Prehistoric Native America: An Encyclopedia''.
1998. .
* Gilmore, Kevin P
''National Register Nomination Form: Franktown Cave. Site 5DA272.''
University of Denver. p. 8-9. Retrieved 9-27-2011.
* Griffin-Pierce, Trudy. (2010)
''The Columbia Guide to American Indians of the Southwest.''
New York:Columbia University Press. .
* Gunnerson, James H. (1987)
''Archaeology of the High Plains.''
Denver: United States Forest Service.
* King, Anthony (2006). Substance Dynamics and Stone Tools at Franktown Cave, Colorado. Unpublished Thesis. Note: An unpublished Thesis is not generally considered a reliable source.
* Kipfer, Barbara Ann. (2000)
''Encyclopedic Dictionary of Archaeology.''
New York:Plenum Publisher. .
* Nelson, Sarah M. (2008). ''Denver: An Archaeological History.'' Boulder, CO: University Press of Colorado. p. 74. .
* Waldman, Carl. (2009) 985 ''Atlas of the North American.'' New York:Facts on File. .
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