Nearly 100,000 people stop at Natural Bridges National Monument in southeast Utah each year but only a fraction of those visitors see its most spectacular vistas. ‚??That‚??s because you can only see them at night,‚?Ě says Ralph Jones, chief ranger at the park.
‚??This is one of the darkest national parks in the country,‚?Ě Jones says, referring to a comprehensive study of night sky quality conducted by the National Park Service.
Just how dark is it? ‚??It‚??s the only Bortle class 2 sky they‚??ve documented,‚?Ě said Chris Luginbuhl of the U.S. Naval Observatory in Flagstaff, Ariz., and a board member of the International Dark-Sky Association. ‚??In plain English that means it‚??s the darkest or starriest sky they‚??ve seen while doing these reviews. The Bortle system is a 10-level scale with one and two being the darkest skies and 10 having the most light pollution.‚?Ě