All the arches now have a link to the Photographer's Ephemeris at the bottom of their pages. The link will take you to their desktop version and put you right at the coordinates that are listed for the said arch. It appears that it is also working on mobile devices, but this feature is mainly for use on computers because of the limitations of the Photographer's Ephemeris on mobile devices (outside the apps). This is added at the request of Ronald Parrott and is a great feature for photographers wanting to get that great light at an arch.