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Fossil Cycad National Monument, Fall River County, South Dakota, USAi
Regional Level Types
Fossil Cycad National MonumentNational Monument
Fall River CountyCounty
South DakotaState
USACountry

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PhotosMapsSearchMineralogy
05312520017272249772542.jpg
Payne and Arnold “Horse Ranch”, Minnekahta, South Dakota.

Fossil Cycad National Monument, Fall River County, South Dakota, USA
08681820017272249775709.jpg
Professor Thomas Macbride, University of Iowa, 1893.

Fossil Cycad National Monument, Fall River County, South Dakota, USA
02704610017272249788936.jpg
Civilian Conservation Corps excavating fossil cycads in 1935.

Fossil Cycad National Monument, Fall River County, South Dakota, USA
05312520017272249772542.jpg
Payne and Arnold “Horse Ranch”, Minnekahta, South Dakota.

Fossil Cycad National Monument, Fall River County, South Dakota, USA
08681820017272249775709.jpg
Professor Thomas Macbride, University of Iowa, 1893.

Fossil Cycad National Monument, Fall River County, South Dakota, USA
02704610017272249788936.jpg
Civilian Conservation Corps excavating fossil cycads in 1935.

Fossil Cycad National Monument, Fall River County, South Dakota, USA
07169220017272249789378.jpg
Payne and Arnold “Horse Ranch”, Minnekahta, South Dakota.

Fossil Cycad National Monument, Fall River County, South Dakota, USA
08681820017272249775709.jpg
Professor Thomas Macbride, University of Iowa, 1893.

Fossil Cycad National Monument, Fall River County, South Dakota, USA
Latitude & Longitude (WGS84):
43° 23' 40'' North , 103° 43' 34'' West
Latitude & Longitude (decimal):
Nearest Settlements:
PlacePopulationDistance
Edgemont739 (2017)13.2km
Hot Springs3,532 (2017)20.7km
Pringle109 (2017)26.1km
Buffalo Gap121 (2017)35.1km
Custer1,952 (2017)42.6km
Mindat Locality ID:
122359
Long-form identifier:
mindat:1:2:122359:3
GUID (UUID V4):
0


An occurrence located 3 miles SW of town.

A fossil cycad is a unique plant that has been silicified in the same manner as petrified wood. A simple description given in Wikipedia is, “Cycads have a rosette of pinnate leaves around a cylindrical trunk.” At the point where the long leaf fronds intersect the “trunk” there is a pronounced diamond shaped leaf scar that distinguishes it from the similar appearance of petrified wood. Specimens of petrified cycads are rarely found in private collections but specimens from this site in the Black Hills of South Dakota reside in many museums throughout the world.

Around 1890 ranchers near Minnekahta, South Dakota began finding fossil cycads and supplemented their incomes by selling them as “petrified pineapples”. Minnekahta was about 11 miles west of Hot Springs at the intersection of highways 18 and 89 but there does not appear to be a municipality there today. In 1892 Thomas H. Macbride, a professor from the University of Iowa, obtained a specimen from a shop in Minnekahta. After analysis this specimen became the holotype specimen for Bennettites dacotensis Macbride, and the scientific community took great interest in the location.

In 1893 Macbride returned to the area at the base of Parker Peak and collected about 40 or 50 additional specimens near the Payne and Arnold horse ranch. There were thousands available and collectors from universities and ranchers-turned-dealers exploited the resource. To preserve this remarkable site, in 1922, President Warren G. Harding created Fossil Cycad National Monument in the Black Hills of South Dakota. Unfortunately the site was not protected and collecting continued. The site was evaluated in 1957 and found to be devoid of specimens and congress removed the site from the National Monument system. Today the land is still owned by the United States government but it is being leased for cattle grazing.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.


Mineral List


1 valid mineral.

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
Quartz
var. Agate
4.DA.05SiO2
var. Chalcedony4.DA.05SiO2
4.DA.05SiO2

List of minerals for each chemical element

OOxygen
O Quartz var. AgateSiO2
O Quartz var. ChalcedonySiO2
O QuartzSiO2
SiSilicon
Si Quartz var. AgateSiO2
Si Quartz var. ChalcedonySiO2
Si QuartzSiO2

Other Regions, Features and Areas containing this locality

North AmericaContinent
North America PlateTectonic Plate
USA

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