Chimney Rock: Ancestral Puebloans and the Moon
Near Pagosa Springs, Colorado
About twenty miles west of Pagosa Springs by road, a sandstone mesa rises from the San Juan National Forest with two towering rock spires at its summit. This is Chimney Rock, the highest-elevation known outlier of the Chaco Canyon cultural system, sitting more than seven thousand feet above sea level on a ridge above the Piedra River valley. Ancestral Puebloans began building at Chimney Rock around the year nine hundred of the common era and occupied the site until approximately eleven hundred fifty.
During those two and a half centuries they constructed about two hundred rooms in ancient homes and ceremonial structures along the ridgeline, from small pit houses to a great house complex near the summit with dozens of rooms arranged close to the twin stone spires. What makes Chimney Rock remarkable even among Chacoan sites is what researchers discovered in recent decades. The two sandstone spires frame a celestial event known as the Northern Major Lunar Standstill, a rare alignment that occurs on an eighteen point six year cycle when the moon rises directly between the pinnacles as seen from particular points on the ridge.
Researchers found that major construction episodes at Chimney Rock, including the great house first built in the year ten seventy-six and expanded in the year ten ninety-three, all coincide with years when this lunar standstill occurred. The builders were tracking the moon with architectural precision, aligning their great house to frame one of the sky's rarest events. President Barack Obama designated Chimney Rock a National Monument on September twenty-first, two thousand twelve, using the Antiquities Act.
Today Navajo, Jicarilla Apache, Ute, and Pueblo peoples maintain living connections to the site and use it for ceremony.
