Geological Features in the Northern Black Hills Area

July 12-17, 2017

Spearfish Canyon Scenic Byway

Spearfish Creek flows 1000 feet below the limestone cliffs it carved along the 20 miles between Spearfish and Lead, S.D.

Several waterfalls grace the canyon.

Scenes for the movie Dances with Wolves were filmed in the area.

At the top of the canyon is 24-acre Iron Creek Lake.

Devil’s Tower National Monument

50 million years ago magma was forced into sedimentary rock above it.  The magma cooled and fractured into columns.  Over time, the sedimentary rock eroded, exposing the monolith Indigenous people call Bear Lodge and Euro-Americans call Devil’s Tower.  President Theodore Roosevelt proclaimed Devil’s Tower the first National Monument in 1906 using the newly-enacted Antiquities Act.  Devil’s Tower is 867 feet from its base and 1267 feet above the Belle Fourche River.  The diameter of the base is 1000 feet.

We walked around the base of the tower, marvelling at the columns and how they curved at the bottom.

Bear Butte State Park

Geologically, Bear Butte is like Devil’s Tower:  Millions of years ago, igneous rock lifted up sedimentary rock layers that were eventually worn away.  Today it stands 1253 feet above the plain.  Historically, human artifacts have been found dating to 10,000 years ago.  Bear Butte has been sacred to Cheyenne and Lakota and was visited by Crazy Horse, Red Cloud, and Sitting Bull.  Trees on the mountain are decorated with prayer ties.

The park advised hiking when temperatures were lower and suggested plenty of water be taken on the 3.6 mile round trip.  We thought we were starting early enough but the temperature was 96 degrees when we returned and was probably higher on the hike itself.  The path was steep, and at times rocky and narrow.  There was almost no shade after the first quarter mile.

Some of the rocks contained dendrites, crystals of iron or manganese oxide that make fern patterns.

Butterflies as big as our palms graced the peak.

The views were wonderful.

Because of the weather conditions, this was our most difficult hike to date.  But, it was beautiful and we were honored to walk the path many had taken before us.