James H . Simpson James Hervey Simpson was an officer in the U . S . Army and a member of the United States Topographical Engineers . Early years . He was born in New Brunswick , New Jersey on March 9 , 1813 , the son of John Simpson and Mary Brunson . He graduated from the United States Military Academy in 1832 and was initially assigned to the Third Artillery . He served in the Second Seminole War and was promoted to first lieutenant in 1837 . Topographical Engineers . In 1838 , a separate department known as the U . S . Army ' s Topographical Engineers was created ( not to be confused with the Corps of Engineers with whom they were merged during the Civil War ) . Lieutenant Simpson was one of the officers transferred to the newly created bureau and assigned as an assistant to Captain W . G . Williams who was in charge of harbor construction on Lake Erie . The following year , he worked on road construction in Florida and then lake surveys in Wisconsin and Ohio . From 1845 to 1847 , he was in charge of the harbor of Erie . New Mexico Expedition , 1849 . In 1849 , Lieutenant Simpson surveyed areas in the American Southwest , between Santa Fe and the Navajo tribal lands . He had recruited wilderness artists Edward and Richard Kern to record the expedition in watercolors , oils , drawings and maps . He survey a road from Fort Smith , Arkansas , to Sante Fe , New Mexico and then served for a year as the Chief Topographical Engineer for the Department of New Mexico . Other Duties . After six months sick leave , Simpson returned to duty and was transferred to St . Paul , Minnesota in 1851 where he spent the next five years overseeing the roads of the territory . During this period , he was promoted to Captain . From June 1856 to February 1858 , Simpson was engaged in coastal survey of Florida . Utah Expedition , 1858 - 59 . In early 1858 , Captain Simpson was ordered to join the Army ' s reinforcements for the Utah War . He and his team resurveyed the trails from Fort Leavenworth to Utah and his photographer , Samuel C . Mills , produced the earliest surviving photographs of features along the trail . Upon his arrival at Camp Floyd , he was directed to open a new road between that post and Fort Bridger . Simpson and his team also surveyed the military reservation at Fort Bridger , at Camp Floyd and in the Rush Valley . In May 1859 , he headed an expedition to survey a new route from Camp Floyd ( south of Salt Lake City ) across the Great Salt Lake Desert of Utah and through the Great Basin to Genoa , Nevada near California . The Army contracted Frederick Lander to immediately to develop the more direct route to California for use by wagons , and Simpson ' s survey was later published in 1876 . Simpson ' s Central Route played a vital role in the transportation of mail , freight , and passengers between the established eastern states and California , especially when hostilities of the Civil War closed the Butterfield Overland Mail stagecoach route that ran along the southern border states . George Chorpenning immediately switched to Simpson ' s route to run his existing mail and stage line , and the Pony Express used it as well . In 1861 the Transcontinental Telegraph was laid along the route , making the Pony Express obsolete . Afterwards , Wells Fargo & Co . hauled mail , freight , and passengers along Simpson ' s route until 1869 , when transportation and telegraphy were switched to the newly completed Transcontinental Railroad . Civil War . He served ( and was captured and released ) in the Civil War , and was eventually promoted to a brigadier general . Later career . Simpson was named chief engineer of the Interior Department . He oversaw the construction of the Transcontinental Railroad , the completion of which made his Central Nevada Route obsolete . In 1880 he retired to St . Paul , Minnesota , and died there on March 2 , 1883 . The Simpson Park Mountains in central Nevada , a small range in west - central Utah ( Simpson Mountains ) , and Simpson Springs Pony Express Station are all named after him . Sources . " Dictionary of American Biography " , vol . IX , p . 179 .