Hackberry Group
About 500 yards east of the Horseshoe structures is the Hackberry Site. Archeologists speculate that Hackberry canyon may have had one of the largest populations of all the Hovenweep units because of the constant seepage of water in the canyon. As many as 250 to 350 people may have lived here. It is unclear if the residents were related or represented different clans and lineages.
The concentrations of structures at both Horseshoe and Hackberry demonstrate the importance of water to the people who lived here. Large multi-story pueblos and towers, located at canyon heads with seeps and springs, are the defining characteristics of the late Pueblo III time period. In this climate, precipitation comes in the form of winter snows, spring rains, and isolated summer thunderstorms. The intermittent rains of summer were crucial to the survival of crops, and Puebloans responded by constructing water-control features. In washes on the mesa tops, small stone dams were built so that sediment could accumulate and water could soak into the ground, flowing slowly into nearby garden plots.
A 23 year-long drought beginning in A.D. 1276, possibly combined with warfare, overpopulation, and limited resources, forced the ancestors of today’s Pueblo people to leave Hovenweep. By the end of the 13th century, Puebloan communities across southeast Utah and southwest Colorado migrated south, joining the pueblos of the Rio Grande River Valley in New Mexico, and the the Hopi in Arizona.