LOOKING FOR THE ANCIENTS or HOW GEOLOGICAL FEATURES
ALLOWED A THRIVING POPULATION OF ANCESTRAL PUEBLOANS TO FLOURISH
When
the ancients moved, they left behind the buildings for a purpose. These places are the kiikiqo or
footprints. These buildings, ashes, pottery,
and petroglyphs were left to show we are connected to the Hisatsinom (Ancestral Puebloans).
Morgan
Saufkie, Bear Clan, Hopi Tribe
Growing up I was always fascinated with history
whether plants or rocks or humans.
Unfortunately, my undergraduate institution did not offer archaeology
courses, or I might have majored in that particular area. However, they did have geology and so I was
off to the races. The closest I came to
working with human history was in my collecting of Pleistocene mammals in
Utah—the State Archaeologist was always after me to look for butchering marks
on the bones. From my point of view, it
was extremely difficult to distinguish these sorts of marks from “natural”
scars. So, I failed at this foray. I always thought that if reincarnated, coming
back as an archaeologist would be nice.
During my three summers of work (early 1970s) as a
Ranger Naturalist in Dinosaur National Monument I became fascinated with the numerous
petroglyphs (painted) and scarce pictographs (chipped and pecked) scattered
around the land. In fact, I tried to
photograph each known glyph—both in color and in black & white. Some glyphs were close to roads and were easy
to access (but often defaced by visitors).
Others were in the back country that required hiking. At that time in my life I could, and did,
walk many miles without problems. The
color camera was a small Pentax with an over the shoulder strap. But wait---the black and white was an old
(and large and heavy) 4 x 5 (inches) piece of work with really great
optics. It also needed to be mounted on
a cumbersome (and heavy) tripod where the “picture taker—me” loaded the negative,
threw a black cloth over my head and camera, and focused, pushed the timer
button, carefully took out and protected the negative, and moved on. Back at the quarry I developed and printed
the back and white negatives. The optics,
plus the large negatives, allowed “really large” enlargements! I often wonder if the monument achieves still
have those photos.
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| The famous lizard petroglyph at Dinosaur National Monument. |
Since my stint with the Park Service I have always
tried to visit older Anasazi sites, mostly near paved roads, during my many
trips to the Mountain West. But wait—sometime
in the past decades I learned the term Anasazi should be replaced by the term
Ancestral or Ancient Puebloans. It seems
the Navajos (Dinè) told the early non-Native American explorers and traders the
Anasazi (meaning ancient enemies) constructed the numerous abandoned pit houses
and pueblos---and the name stuck until recently.
I am an avid reader of Mountain West history and long
ago decided that Hovenweep National Monument, northeast of Bluff, Utah, was on
my Bucket List. The Monument is one of
those places that is a destination point and not a “dad, let’s pull off to see
the Indian ruins as I need to potty.” One
needs to “be going” to Hovenweep in order to get there!
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| Map, courtesy of USGS, showing location of Hovenweep National Monument northeast of Bluff on the Utah-Colorado State Line. |
So, off we go through a narrow canyon leaving the cozy
campground at Bluff (see Post July 18, 2018) and heading north towards Blanding, Utah, on
U.S. 163. The summit of the canyon is a
broad plateau held up by the Jurassic Bluff Sandstone (which may be a local
stand-alone formation or a local member of the Morrison Formation).
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| The Bluff Sandstone forms a narrow canyon along the highway leading out of Bluff and also is the caprock of a broad plateau at the summit. |
After
about 10 miles of travel Utah 262 takes off to the right (east) heading to Hovenweep;
follow the signs and don’t wander off. Along the way there are a few outcrops
of Late Jurassic Morrison Formation; however, the roads traverse mostly on the overlying Cretaceous Dakota Formation. This highland is part of the Great Sage Plain,
named not for a geomorphic expression of landscape but for a plant, big
sagebrush (Artemisia tridentata). The Plain ranges in elevation from about
7000-5000 feet and is part of Colorado Plateau Physiographic Province. The
Plain stretches from near Monticello and the Abajo Mountains (north of
Blanding) southeast to the San Juan Mountains in southwestern and is home to
the largest concentration of Ancestral Puebloan structures in the U.S. The Cajon Mesa is a particular subsection of
the Plain and is the location of Hovenweep.
What attracted these early Americans to Cajon
Mesa? Well, the same thing that attracts
farmers to land today—water and soils capable of growing crops. But I could say that geology attracted the
Ancestral Puebloans. Soil developed on
the Plain via wind-blown sand and clay (termed loess) and probably was
associated with winds from the southwest during the last 10,000-12,000 years. These loessal soils can be quite rich when
water is available. On the Cajon Mesa
the Dakota Formation (Cretaceous) forms the upper rimrock and is composed of
sandstone and mudstones with a few beds of poor coal. The Dakota is a mixture
of stream, swamp and maybe some beach sands as the unit represents an initial
transgression of marine waters onto the continental western interior. In fact, we term this great inland sea the
Western Interior Seaway and it stretched from Utah to Minnesota and Missouri
and from Alaska to the Gulf of Mexico.
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| Dakota Formation, the caprock at Hovenweep. |
Below the Dakota Formation is the Burro Canyon
Formation, also of Cretaceous age but older than the Dakota, that is composed
of a variety of braided stream-deposited
rocks: conglomerate, sandstone, shale, mudstone, limestone and tightly cemented
quartz sandstone (wrongly termed quartzite).
So, when water does arrive in the form of summer monsoon rains or winter
snows it gathers in pot holes on the rimrock massive sandstone, or seeps into and
through the Dakota rocks until it reaches the Burro Canyon, a rather impervious
layer. At that point the water begins to
move horizontally and when it reaches the canyon at Hovenweep it forms seeps or
springs. The inhabitants were then able
to capture the water by use of dams.
On Cajon Mesa the Ancestral Puebloans constructed
terraces to funnel rain water and dams to catch the water so that crops (mainly
corn, beans and squash) could be irrigated. The inhabitants were farmers rather
than hunters-gathers that preceded them.
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| The Burro Canyon Formation underlies the Dakota Formation at Hovenweep. Part of the formation is a very indurated conglomerate. Photo courtesy National Park Service. |
Geology also played other important roles. For example, the sandstone layers in the
Dakota provided the masonry blocks for construction of the towers and
buildings. Some of the conglomerate beds
in the Burro Canyon contain numerous chert and flint cobbles that
provided material for projectile points.
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| Masonry blocks used to construct the buildings at Hovenweep were quarried from the Dakota Formation--without the aid of steel chisels to shape. |
The six groups of masonry structures at Hovenweep were
constructed by Ancestral Puebloans who first settled in the area ~500 A.D. and
farmed portions of the Cajon Plateau and parts of the inner canyons (hunters and gatherers, temporary residents, were probably in the area ~8000-5000 BC until the Ancestral Puebloans arrived ). As noted above, they built terraces and water
dams and granaries; the latter storage areas were in the canyon to better protect crops
like corn. But as the population soared
(~2500?) , workers needed to travel further away “from their canyon home” to
collect wood and plant/harvest crops.
Archaeologists believe the population peaked between 1200-1300 A.D. and
soon after that they, like the inhabitants of Mesa Verde and other living
centers, left the area to start a new life in the Rio Grande and Little
Colorado River valleys. Researchers are
uncertain about this move but suspect drought, warfare and overpopulation. Does this ring a bell today?
As a native Kansan I often wonder if the population of western Kansas will decrease significantly when irrigation waters of the Ogallala Aquifer are depleted? What happens when Lake Mead on the Colorado River cannot provide enough water for the agriculture and growing population of California and Arizona? Should valuable water of Arizona be used to irrigate cotton and alfalfa in the desert? Where will the people of Syria go since their country's infrastructure is essentially destroyed? As climate change moves forward where will large populations along the U.S. coasts migrate (after being flooded out from rising sea level)? Maybe Elon Musk will take us to Mars!
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| Tower Point Ruin. We come here to visit our ancestors. They are all around. (Victor Sarracino, Water Clan, Pueblo of Laguna) |
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| Twin Towers. Through the strength of the spirits, our ancestors built these dwellings here (Ernest m. Vallo, Sr., Eagle Clan, Pueblo of Acoma). |
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| Montezuma Castle. Photo courtesy National Park Service. |
One of the great views at Hovenweep is to the east and
of Ute Mountain or Sleeping Ute Mountain not far over the line in
Colorado. Like other isolated mountain
ranges (~12 x 5 miles with a topographic relief of ~4000 feet and an elevation
of ~9984 feet) in this section of the Colorado Plateau, Sleeping Ute Mountain
is a laccolithic range---overlying sedimentary rocks have been domed up by the
rising igneous magma and then the less-resistant rocks were eroded. Unlike the other Plateau mountains such as
the Henry Mountains, the Abajo Mountains and the La Sal Mountains, the Sleeping
Ute Mountain was intruded into overlying rocks in the Late Cretaceous ~72
Ma. The other ranges are much younger,
perhaps ~25-28 Ma in the Tertiary. The
name comes from the profile of a Ute warrior lying on his back with his arms
folded. Sleeping Ute Mountain is not on a “main
road” and is situated inside of the Ute Mountain Ute Reservation and plays a
role in some of their ceremonies.
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| Sleeping Ute Mountain as viewed from Hovenweep. Dakota Formation as caprock. Photo courtesy National Park Service. The Hopi name for Sleeping Ute Mountain is Hon tsomo or Bear Mountain (Consensus of Elders, The Hopi Tribe). |
President Warren G. Harding was correct when in 1923 he
established a national monument preserving the amazing structures built by a
group of Ancestral Puebloans. Many readers may have visited the structures at
nearby Mesa Verde National Park (established 1906) but if travelers are in the
area get a map and take the detour to Hovenweep National Monument. It is a great place to learn how these
ancient Americans understood geological processes and used them in their
everyday living. It is an amazing place
and I can check it off my bucket list!
