Thursday, August 22, 2013


Geologists are historians; it is just that we study “older things” than someone termed a “modern” historian. However, at times the landscape gives us a chance to study both issues—geology and modern history. Such is the case at Slim Buttes, South Dakota.
The northwest section of South Dakota, essentially Harding County bordered on the west by Montana and the north by North Dakota, displays a variety of geologic wonders that few out-of-state travelers ever observe.  The country is occupied by a few ranchers with the 2010 census listing the county population as 1255.  Buffalo, the county seat, has 330 persons living in the town.  However, Harding County is a wonderful locality to explore but make certain the vehicle gasoline tank is filled before leaving town!

West face of South Cave Hills.  Photo courtesy of USGS; taken in 1911.
I consider the county worth a visit anytime I am in the vicinity---for a couple of reasons: 1) the Late Cretaceous rocks representing the end of the Western Interior Seaway and the overlying Cenozoic rocks exhibiting indicators of swampy conditions are nicely exposed; and 2) there are several high hills exposing rocks belonging to the Oligocene/Eocene White River Group (Chadron and Brule Formations) and the overlying rocks of the Oligocene-Miocene Arikaree Group (in South Dakota divided into the Rosebud, Harrison Turtle Butte, Monroe Creek and Sharps Formations [USGS terminology]).  The best exposures of these Tertiary formations are found in a series of high hills known as the Short Pine Hills, Slim Buttes, the Cave Hills and others including my favorite name “Hills Where the Crows Were Killed” but unfortunately known today simply as Crow Butte. Apparently (not many records) in 1822 Lakota and Crow Native Americans got into a battle seemingly with the Crows coming out on the short end.
One particular area of interest, at least to me, is Slim Buttes in the southwestern part of Harding County.  These topographic highs are a very rugged area with a relief of perhaps 600 feet above the rolling prairie. The buttes preserve Tertiary rocks, White River and Arikaree Groups (Eocene to Miocene, similar to the “badlands” of southwestern South Dakota), sitting on top of the Paleocene Ludlow Formation (Ft. Union Group) and its  somber gray-colored, exposures.  Deep canyons and steep cliffs abound in the buttes and it is truly a peaceful place with very nice road cuts (various types of cryptocrystalline quartz) and fantastic scenery. Vertebrate fossils are also present but unavailable for collecting since the accessible land is managed by a federal agency---Custer National Forest.

South face of Slim Buttes. Arikaree cliff face with White River Group below. Photo courtesy of USGS; taken in 1911.

Arikaree Group slump on rocks of the White River Group, Slim Buttes. Photo courtesy of USGS (1953).
I would be very careful, however, about drinking water from any of the springs at the base of the cliffs as the water contains uranium at ~200 parts per billion. There are several abandoned uranium (carnotite) mines in the buttes and leakage has caused some contamination. Uranium was mined from the Chadron Formation when water leached minerals from the overlying radioactive tuffs of the Arikaree Group (Gill and Moore, 1955). 

The Castles National Natural Landmark.  Photo National Park Service.
In 1976 an area (987 acres) known as The Castles was designated as a National Natural Landmark.  Managed by Custer National Forest the Castles are:  Steep-walled, flat-topped buttes standing 200 to 400 feet above the surrounding prairie, The Castles contains exposed rock of Upper Cretaceous, Paleocene, Oligocene, and Miocene Ages. Cretaceous and Tertiary beds contain a variety of flora and fauna fossils. (  There also are hundreds of acres associated with Slim Buttes that are privately held.

General George Crook had a distinguished career (from a perspective in Washington, DC) in the Civil War, the Great Sioux War of 1876-77, and the Apache War. Photo from Library of Congress.

One of Crook’s camps, 1876.  Photo from U.S Archives.
That was the geology report and now for the historical aspects.  In June 1876, George Custer had suffered his inglorious defeat at the Battle of the Little Bighorn in southeastern Montana. The U.S. Army was rather stunned by results of the battle and decided that members of the Lakota and Cheyenne Native American groups must be punished and forced back to the reservations. Therefore, General Phillip Sheridan sent General Alfred Terry and General George Crook to southeastern Montana and western South Dakota to hunt for “hostiles” in drainage basins of the Powder, Rosebud, Heart, and Tongue rivers. It was a wet late summer in the region (causing all sorts of logistical problems with the resulting name "horsemeat march") so Crook set his sights on the northern Black Hills and much needed supplies.  Terry decided to forgo the trek and returned to base camp at Fort Abraham Lincoln.

Ft. Abraham Lincoln was located along the Missouri River near the present site of Mandan, North Dakota, opposite Bismarck (the current sate capital).  The Fort's commander, until that fateful day in June, 1876 , was Lt. Colonel 
George Custer.  It was from this site in North Dakota that Custer and his troops headed west to their ending journey at Little Bighorn with the band playing a rousing rendition of that Irish quickstep, Garryowen (the regimental song).  We all know, as Paul Harvey would say, "the rest of the story".


Philadelphia, July 8, 1876
General William T. Sherman, Washington, D.C.:
The following just received from Drum, and forwarded for your information,

Chicago, Ill., July 7, 1876 --- 1.10 a.m.

General P. H. Sheridan, U.S.A.,
Continental Hotel

The following is General Terry's report, received late at night, dated June 27:
"It is my painful duty to report that day before yesterday, the 25th instant, a great disaster overtook General Custer and the troops under his command. At 12 o'clock of the 22nd instant he started with his whole regiment and a strong detachment of scouts and guides from the mouth of the Rosebud; proceeding up that river about twenty miles he struck a very heavy Indian trail, which had previously been discovered, and pursuing it, found that it led, as it was supposed that it would lead, to the Little Big Horn River. Here he found a village of almost unlimited extent, and at once attacked it with that portion of his command which was immediately at hand....
So, Crook was hungry and not having much success with the "hostiles", and decided to send a contingent ahead of his main force.  In early September Lt. Anson Mills and ~150 members of the 3rd Cavalry, heading to Deadwood in the Black Hills, came upon the village of American Horse (Lakota but with other members from the Minneconjous, Brules, and Cheyennes) in the Slim Buttes. A battle ensued with the numerically-superior Cavalry killing several tribe members (including American Horse), capturing others, and burning the village. For the Cavalry it was a particularly satisfying battle since the lodges of American Horse contained several items that belonged to members of Custer’s 7th Cavalry including the guidon of Company I and the blood-covered gauntlets of Captain Myles Keogh.  However, the battle was not over as the Oglala Lakota warrior Crazy Horse, along with several hundred warriors, was nearby and upon learning of the battle with American Horse rushed to the site only to find that Crook and his main column had arrived. A somewhat minor skirmish erupted with the Native warriors mostly firing from the top of the cliffs; however, few lives were lost on either side.

Crook and the troops finally made it to Deadwood a week later (the "starvation march of 1876") with Crazy Horse still on his tail and harassing his movements. However, the Army was able to claim victory at Slim Buttes, especially welcome after Little Bighorn, and in reality this was the beginning of the end for the Lakota and Cheyenne nomadic tradition. Or perhaps, Little Bighorn was the beginning of the end?
The last time I visited Slim Buttes a few years ago I plopped down on a cliff, consumed my lunch, and wondered about 1876. Today it is such a beautiful and peaceful area it is hard to imagine the “hard times” so many years ago. My only suggestion, is that if for some reason you are in the vicinity, take a small tour through Reva Gap (SD 29) and Slim Buttes (SD 79).  If you do the trip snap a few photos for me as mine were eaten by a computer gremlin!

Instead of spa we'll drink down ale,
We'll beat the bailiffs out of fun,
And pay the reck'ning on the nail;
We'll make the mayors and sheriffs run;
No man for debt shall go to jail
And are the boys no man dares run,
From Garryowen in glory.
If he regards a whole skin.

         Lyrics to Garryowen.


Gill J. R. and G. W. Moore, 1955, Carnotite-bearing Sandstone in Cedar Canyon, Slim Buttes, Harding County, South Dakota:  USGS Bulletin 1009-I.

Jerome A. Greene---Slim Buttes, 1876: An Episode of the Great Sioux War.

Fred H. Werner---The Slim Buttes Battle, September 9 and 10, 1876.


  1. I have a few pictures of the view going through the Reva Gap. Let me know how to send them to you. I can also get a shot of the Info Board at Crow Buttes.

  2. Great. Send me a few at mike

  3. hopefully this is a typo...

    "1) the Late Cretaceous rocks representing the end of the Western Interior Seaway and the overlying Paleozoic rocks"