The Arkansas mounds that predate Cahokia and still mystify archaeologists today

Plum Bayou Mounds

Between 650 and 1050 CE, the Plum Bayou people built 18 earthen mounds on an oxbow lake in Arkansas. They positioned several mounds to align with sunrise and sunset on solstices and equinoxes, creating an earthen calendar for farming and ritual cycles.

The site served as the primary religious center where only a few leaders lived but many came for ceremonies. Then around 1050 CE, they vanished without a trace.

Here’s their story, preserved at a state park you can walk through today.

Builders of the Sacred Site

The Plum Bayou people grew from the earlier Baytown culture that lived in the area from 300 to 650 CE. Most lived in small villages along the Arkansas and White Rivers, not at the ceremonial site.

Only religious and political leaders lived at the complex full-time. The rest of the people came only for ceremonies.

Their society had few differences between leaders and regular people, unlike later cultures. The site served as the main gathering place for all nearby Plum Bayou communities.

Carrying Soil Basket by Basket

Workers built these huge mounds using just simple tools and raw strength. They used pointed sticks hardened in fire to dig up soil, then carried it in baskets to the building site.

When archaeologists dig into the mounds today, they can see different colored soil layers showing each basket load. Builders placed each mound in an exact spot according to a careful plan.

Most mounds had flat tops where wooden buildings stood for ceremonies and homes for leaders.

Tracking the Sun with Earthen Calendar

The builders placed several mounds to line up with the sunrise and sunset during key times of the year. These alignments formed a calendar that helped track when to plant crops and hold ceremonies.

When the sun sets during summer solstice, it aligns perfectly between Mounds B and H. This knowledge helped the people plan their farming and religious events.

Builders used a standard measurement of 155.8 feet between mounds to create these precise sun alignments.

Feasting on Ceremonial Grounds

At least two mounds show signs of big feasts. Archaeologists found ancient trash piles with lots of burned animal bones, mostly from deer.

Mound S contains many food remains along with cutting tools and broken pottery used for cooking and serving. These finds show that shared meals played a key role in their ceremonies.

Deer meat was clearly the favorite food at these gatherings. The large amount of bones shows many people took part in these feasts.

Gardens and Gathered Foods

The Plum Bayou people grew food in small garden plots rather than big fields. They raised plants like maygrass, little barley, amaranth, and chenopodium – all plants with small, nutritious seeds.

They also grew squash and sunflowers and gathered wild plants from the forests and wetlands. Unlike their neighbors, they didn’t rely much on corn farming.

Scientists found burned seeds from a mystery plant they call “Type X” that might be a special crop the Plum Bayou people developed.

Waterways and Trade Routes

The ceremonial site sat on a lake that connected to wider water routes. People traveled by canoes made from hollowed-out logs using fire and scraping tools.

Trade goods found at the site came from far away. These include quartz crystals from the Ouachita Mountains, copper from the Great Lakes, and seashells from the Gulf of Mexico.

These treasures show that despite their simple tools, the Plum Bayou people traded with groups hundreds of miles away.

Sacred Ceremonies in Open Plazas

The mounds surrounded two large, open areas where people gathered for ceremonies. Villagers from all over the region traveled to the site for important events.

Celebrations during solstices and equinoxes marked key points in their yearly calendar. The alignment of the mounds with the sun highlighted these special days.

The layout of the whole site reflected their beliefs about how the universe worked, with the mounds and plazas mirroring their view of the spiritual world.

Organizing Their Society

Leaders lived at the ceremonial complex year-round. They directed building projects, led ceremonies, and organized feasts that brought communities together.

Leadership likely passed down through families. Their society had fewer social divisions than later cultures in the region, with less difference between elites and common people.

The size of the mounds shows these leaders could gather large work groups for big projects despite having only simple tools.

Neighbors Across the River Valleys

The Plum Bayou people had contact with several nearby groups. They traded with the Coles Creek people along the Mississippi River and early Caddo groups in the western river valleys.

They also connected with early Mississippian cultures to the northeast. Around 1000 CE, these Mississippian groups began spreading throughout the region with their more rigid social ranks and intensive corn farming.

The Plum Bayou culture lasted about 50 years alongside these Mississippian neighbors before their traditions began to fade.

Mysterious End of Ceremonies

Around 1050 CE, the Plum Bayou people stopped using their ceremonial complex. By 1100 CE, they no longer built mounds or held their traditional ceremonies at the site. We don’t know exactly why they abandoned the complex.

The people continued living in the region but stopped maintaining their sacred centers. Later Native Americans sometimes used the old mounds for their own ceremonies and burials, treating the ancient structures as sacred places.

Visiting Plum Bayou Mounds Archeological State Park

You’ll find Plum Bayou Mounds Archeological State Park at 490 Toltec Mounds Road near Scott, Arkansas, about 20 miles southeast of Little Rock.

For the best experience, time your visit during solstice or equinox celebrations when you can witness the solar alignments.

The Knapp Trail (0.75 miles) offers an accessible route, while the Plum Bayou Trail (1.6 miles) provides a more comprehensive tour of the mounds and lake.

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