Chimney — Rock National Monument Protecting ancient masonry from erosion and freeze-thaw cycles. Every 18.6 years, the moon reaches its northernmost rising point on the horizon. From the vantage point of the Great House, the moon appears to rise directly between Chimney Rock and Companion Rock . chimney rock national monument Chimney Rock is considered a "Chacoan outlier," a satellite community of the vast Chaco Canyon civilization centered in New Mexico, roughly 100 miles to the south. It represents the highest elevation of any known Chacoan site. chimney rock national monument
