Gills Added Station, used by the Pony Express Company under the name "Gills" and also called "Sand Hill" for the prominent sand hills just north, was an added station created for the new July 1, 1861, post office mail contract that required near-daily stagecoach service in both directions. Because the original station sites were too far apart for this new service, added stations were built from the Missouri River to California, increasing the route from around 87 stations to around 144 station sites, and these new sites were also used by the Pony Express. "Gills" is on a true azimuth of 256 degrees and 1.949 miles from this monument.