The U.S. Senate’s National Parks Subcommittee held a hearing on a bill Wednesday that would designate 4,726 acres around the Chimney Rock Archaeological Area in southwest Colorado, near Pagosa Springs, a national monument, according to The Associated Press. The designation, proposed by Senator Michael Bennet and Congressman John Salazar, both Colorado Democrats, would provide the area with further protections under federal law. The site was the home of ancestral Puebloans some 1,000 years ago, and it remains of spiritual and cultural significance to their modern-day descendants, according to Indian Country Today. Every 18.6 years, the moon rises between the ancient towers at the site. “Much remains unknown about the Chacoan people and the site itself, but clearly it was a site of astronomical and religious significance, and it’s certainly a very important archeological site,” says Senator Mark Udall, a Colorado Democrat and bill co-sponsor, in his opening statement as chair of the subcommittee hearing.