Gator Girl Rocks

Rockhounding South Dakota

South Dakota is an extraordinary state for rockhounding.  South Dakota is well known for its Black Hills’ gold and pegmatites (including the legendary ninety ton giant spodumene crystal from the Etta Mine as well as huge beryl crystals).  The state also is well known for its Fairburn agates and, sadly, collectors and vandals who destroyed a national monument.  The state is home to fabulous National Parks and Monuments that are of tremendous interest to rockhounds.  South Dakota also has some amazing caves, including Jewel Cave - the second longest cave in the world (located in Jewel Cave National Monument).  Finally, there are about a dozen sites – throughout South Dakota – where meteorites have been found.

 

State Rocks, Gemstones, Minerals, Fossils, & Dinosaurs

Rockhounding Tip:  Knowing state rocks, gemstones, minerals, fossils, and dinosaurs often can be very useful information for rockhounders.  Ordinarily, states with significant mineral deposits, valuable gemstones, fossils, or unusual or significant rock occurrences will designate an official state mineral, rock/stone, gemstone, fossil, or dinosaur to promote interest in the state’s natural resources, history, tourism, etc.  Accordingly, such state symbols often are a valuable clue as to potential worthwhile rockhounding opportunities.

State Gemstone:  Fairburn Agate (1966)
South Dakota designated the Fairborn agate as its official state gemstone in 1966.  These agates were first discovered near Fairborn, South Dakota.  Fairborn agate is a variety of agate known as fortification agate, or agate with sharp-angled bands that resemble the outlines of fortifications of a castle.  These bands are a variety of colors including white, brown, tan, reddish, & black.  The agates formed as marine sedimentary agates in limestone approximately 330 – 250 million years ago.  The agates are harder than the limestone and erode out over time.

 

State Mineral:  Rose Quartz
South Dakota designated rose quartz as its official state mineral in 1966.  Rose quartz is colored reddish or more commonly a light pink by small amounts of titanium.  Typically, rose quartz is coarsely crystalline (meaning the crystals are quite large). 
 Generally, the crystals do not have external faces because of interference from other growing crystals.  Rose quartz is an igneous mineral that originates deep within the earth's crust.  It forms from the solidification of granitic 
magma (molten rock).  In South Dakota, rose quartz is found in pegmatites in the southern Black Hills area.  These pegmatites are associated with 
the Harney Peak granite mass (which is now exposed at the surface of the earth because of erosion).  Geologists estimate that there are thousands of pegmatite intrusions in the Black Hills region.  These pegmatites 
formed during the Precambrian and are over 1.5 billion years old.

 

State Fossil:  Triceratops (1988)
Prior to 1988, South Dakota's state fossil was the cycad, a type of palm-like Mesozoic plant known from Cycad National Monument near Minnekahta.  Illegal collecting and vandalism, however, destroyed the Monument.  Seriously.  Accordingly, in 1988, South Dakota designated Triceratops as its official state fossil (replacing the cycad).  Triceratops is a genus of herbivorous ceratopside dinosaur that lived during the Late Cretaceous Period about 66 to 68 million years ago near the end of the ‘Age of Dinosaurs.’  It was one of the last dinosaur genera to appear before the great Cretaceous-Paleocene extinction event.  The name Triceratops is derived from Greek words to mean “three-horned face.”  The South Dakota Triceratops fossils have been found in rocks from the Hell Creek Formation in the northwestern part of 
the state.  A nearly complete Triceratops horridus skull was found in Harding County, South Dakota in 1927.  The 
Harding County specimen is on display in the Museum of Geology at the South Dakota School of Mines and Technology in Rapid 
City.    

 

Rockhounding Resources

South Dakota Geological Survey

U.S. Bureau of Land Management – South Dakota Office

 

Fossil Freeway
The Fossil Freeway is a useful website for South Dakota and Nebraska that identifies some of the rich fossil areas between Nebraska's Panhandle and The Black Hills in South Dakota.

 

• Roger Clark, South Dakota State Gemstone - Fairburn Agate (2009).
• John Paul Gries, Roadside Geology of South Dakota (1996).
• June Culp Zeitner, Midwest Gem, Fossil, & Mineral Trails: Prairie States (Rev. ed., May 1998 – first published in 1955). 
• June Culp Zeitner, Midwest Gem Trails: Field Guide for the Gem Hunter, the Mineral Collector, and the Tourist (3d. Rev. ed., 1964 – originally published in 1956).
• Allan W. Eckert, Earth Treasures Vol. 3 - Northwestern Quadrant (1986; reprint in 2000).
• James Martin Monaco & Jeannette Hathway Monaco, Fee Mining & Rockhounding Adventures in the West (2d ed. 2007).
• Kathy J. Rygle & Stephen F. Pedersen, Northwest Treasure Hunter's Gem & Mineral Guide (4th ed. 2008).

 

Museums of Interest to Rockhounders

South Dakota Museum of Geology
South Dakota School of Mines and Technology – Rapid City, South Dakota
The Museum offers world-class displays of rare real fossils and minerals.

 

Museum at Black Hills Institute
Black Hills Institute of Geologic Research – Hill City, South Dakota
The museum contains an extensive collection of dinosaurs, marine fossils, minerals, meteorites, and local paleontological historical displays.

 

Black Hills Mining Museum
Lead, South Dakota
The museum focuses on local historic gold mining including a simulated underground gold mine.

 

Homestake Gold Mine Visitor Center
Lead, South Dakota
Commercial business.  Homestake is an underground and open-pit gold mine.  Visitors can tour surface and learn about gold mining.

 

Places to Visit - Interesting Sites To See

Badlands National Park
Southeast of Rapid City, South Dakota
Badlands National Park includes geologic deposits that contain one of the world's richest fossil beds.  Ancient mammals such as the rhino, horse, and saber-tooth cat once roamed here.

 

Wind Cave National Park
South of Rapid City, South Dakota
Wind Cave was the first cave to be designated as a national park (1903).  Wind Cave National Park is one of the world's longest (over 136 miles) and most complex caves and is well known for its outstanding display of boxwork, an unusual cave formation composed of thin calcite fins resembling honeycombs.

 

Jewel Cave National Monument
West of Custer, South Dakota
Jewel Cave National Monument, located less than 40 miles from Wind Cave National Park, is a unique world of sparkling calcite crystals and other spectacular cave formations. Jewel Cave is the second longest cave in the world (over 150 miles).

 

Mount Rushmore National Memorial
Southwest of Rapid City, South Dakota
The Mount Rushmore National Memorial is carved into the Harney Peak granite batholith in the Black Hills.  The batholith magma intruded into the existing rock over 1.5 billion years ago.

 

The Mammoth Site
Hot Springs, South Dakota
The Mammoth Site is the world’s largest mammoth research facility.  The site is a working paleontological site/museum that contains the largest concentration of Columbian and Woolly mammoths ever found in their primary context (where they died) in the world.  The mammoths were trapped in a karst sinkhole during the Pleistocene era (Ice Age).  The mammoth bones were discovered in 1974 and a museum and building enclosing the site was constructed.

 

The Former Fossil Cycad National Monument
Fall River County, South Dakota
Beginning in 1922, Fossil Cycad National Monument was a U.S. national monument.  The site, encompassing approximately 320 acres, contained hundreds of fossil cycads.  Because people, however, stole or destroyed all of the visible fossils, the site was withdrawn as a national monument in 1957.  A truly sad comment on people.  In 1980, construction of a highway through the site uncovered more fossil cycads.

 

Pillars of the Nation
Sioux City, South Dakota
Located in McKennan Park, Pillars of the Nation was erected in 1941 just before America entered World War II.  The McKennan Park caretaker (Oscar Ellefson) envisioned having two pillars made of stones native to each of the then 48 states.  Some states, such as Ohio and New York, contributed stones in the shape of the state.  Other states contributed carved stones.  In addition to the two ‘pillars of the nation’ pillars, there are two additional pillars made from stones native to South Dakota.

 

National Rockhound & Lapidary Hall of Fame
Murdo, South Dakota
Located within the Pioneer Auto Museum, there is a small exhibit of rocks, minerals, and fossils.

 

Petrified Wood Park
Lemmon, South Dakota
Tourist attraction.  Petrified Wood Park was built in the early 1930s, donated to the city in the 1950s, and renovated at the turn of the century.  The site includes a museum with petrified wood.

 

Badlands Petrified Gardens
Kadota, South Dakota
Commercial business (tourist attraction).  Features a collection of petrified wood as well as rocks, minerals, and fossils.

 

Caves
Black Hills Area, South Dakota
There are a variety of commercial business caves in the Black Hills area.  The caves systems typically feature stalactites, stalagmites, flowstone, and other cave formations.

 

Rockhounding Sites for Children & Families

Badlands Specimens
Buffalo Gap National Grassland – Southwestern South Dakota
Federal law prohibits collecting in the Badlands National Park.  The Buffalo Gap National Grassland (which covers over half a million acres), however, does allow certain collecting subject to federal restrictions.  Recreational rockhounds may find Fairburn agates as well as other agates, jasper, rose quartz.  Lawfully collected specimens may not be sold or traded.

 

Black Hills National Forest
The Black Hills National Forest does allow certain collecting subject to federal restrictions.  Lawfully collected specimens may not be sold or traded.