Earth Notes: Mesa Verde’s Spruce Tree House
Spruce Tree House is often the first cliff dwelling most visitors see when they arrive at Mesa Verde National Park in southwest Colorado. From the rim, people’s eyes begin to focus in on a sandstone alcove that shelters the superb architecture of the ancient dwelling.
Many have taken the short trail down to the site—but not this year. The park decided to close the structure to the public after a rock fall in 2015, and remains off limits until work can be completed to make it safe to enter again.
Rock falls are nothing new. The Ancestral Puebloans who built Spruce Tree House in the early 1200s certainly experienced erosion of their rockbound homes. And since Mesa Verde became a national park in the early twentieth century, Spruce Tree House has seen stabilization efforts. Early archaeologist Jesse Walter Fewkes worked in the site, and the park service shored up a crack system in the 1960s.
Shortly after the most recent rock fall, a climbing crew did a preliminary assessment. Then modern geoengineering methods were applied, including remote-sensing LIDAR to draw a profile of the structure, followed by a three-dimensional engineering analysis. Plans and specifications are being drawn up to direct actual stabilization—pinning long metal rods into the alcove face—work that’s expected to happen in the next year or two.
Mesa Verde holds the greatest concentration of cliff dwellings in the country, and most of those sites are open. But for a while longer, visitors will need to be content viewing Spruce Tree House from a distance.