Almon Harris Thompson Almon Harris Thompson ( September 24 , 1839 – July 31 , 1906 ) , also known as " A . H . Thompson " , was an educator , topographer , geologist , explorer , and Civil War veteran . Often called " The Professor " or simply " Prof " , Thompson was second in command of John Wesley Powell ' s Second Expedition , a federally - funded expedition to explore the Green and Colorado Rivers , Colorado drainage and canyons , and map southern Utah and northern Arizona . Thompson ' s diary of Powell ' s Second Expedition ( 1871 – 1875 ) was originally published in the Utah Historical Quarterly in 1939 . Through his work on the Powell expeditions and later as geographer at the US Geological Survey , he was responsible for naming many geographic locations in the west . Thompson is also known for his involvement in the formation of the National Geographic Society . Early life and education . Thompson was born on September 24 , 1839 in Stoddard , New Hampshire . Later , his family moved to Southborough , Worcester , Massachusetts ( 1848 – 1856 ) where he attended school . Thompson enjoyed mathematics and science . Thompson attended Wheaton College ( 1857 – 1861 ) in Illinois where he met John Wesley Powell . After graduation , he married Ellen Louella ( Nellie ) Powell ( 1840 – 1909 ) , the sister of John Wesley Powell on July 8 , 1862 in Wheaton , Illinois . They had no children . On May 16 , 1864 , Almon H . Thompson enlisted in the United States Army noting his residence as Hennepin , Illinois . He was commissioned as an officer in Company B , Illinois 139th Infantry Regiment on June 1 , 1864 . Thompson was part of the Hundred Days Men enlistment program near the end of the Civil War . He mustered out in Peoria , Illinois on October 28 , 1864 as a 1st Lieutenant . After the war , Thompson served as superintendent of schools at Lacon ( 1865 – 1867 ) and Bloomington , Illinois ( 1867 – 1868 ) . In the 1870 census , Thompson is listed as living in Normal , Illinois with his wife Ellen , mother Mary , as well as Emma and John Powell . Both Thompson and Powell are listed as school teachers . Expeditions . In 1867 , Thompson ' s brother - in - law , John Wesley Powell , put together an expedition to the Rocky Mountains to collect specimens for the Illinois State Natural History Society . Thompson acted as the entomologist of the party . After the expedition , in 1868 , Thompson resumed the superintendency of the Bloomington , Illinois schools . He was appointed acting curator of the Illinois Natural History Society in 1869 . In 1870 , Powell and Thompson began plans for what is known as Powell ' s Second Expedition , exploring the Colorado River and surrounding plateau country . They secured supplies at Fort Bridger and Salt Lake City to be shipped to three locations along the expedition route . The group set out from Green River , Wyoming in May 1871 with the geographical work in Thompson ' s hands . He served as chief topographer and geographer , and was in charge of field operations when Powell was absent . Because Powell was often away from the work site , Thompson was often in charge . The explorers mapped much of Utah and northern Arizona while on a boat journey from Green River to Lees Ferry . In addition to the river survey , Thompson also led a significant overland expedition . Along with other members of the Survey , he left Kanab , Utah on May 30 , 1872 to identify a passage to the mouth of the Dirty Devil River where the Second Expedition crew had stored a boat . Their route led them along the Paria River , in the southern end of the Aquarius Plateau , over Boulder Mountain , through the Waterpocket Fold , and across the Henry Mountains . After finding the boat , Thompson mapped a return route overland while other members of the group took the boat downstream . In Chapter X : Report on a Trip to the Mouth of the Dirty Devil River in the Exploration of the Colorado River of the West , Thompson describes his experiences . During this trip , he named the Escalante River , the last river of the contiguous United States to be identified . He was also the first Euro - American to reach the summit of the Henry Mountains . He named it Mount Ellen after his wife . Powell gave Thompson credit for his work in the Preface of one of their reports stating , " Professor A . H . Thompson has been my companion and collaborator during the greater part of the time , and has had entire charge of the geographic work ; the final maps will exhibit the results of this learning and executive ability " . Ellen Powell Thompson accompanied her husband on some of the activities including trips into the mountains and boating the rapids of southern Utah . While residing in Kanab , Utah in 1872 , she collected and identified many new types of plants . Under Thompson ' s direction , the team created the first preliminary map of the southern Utah region in the winter of 1872 – 73 . Ultimately , Thompson constructed maps of Utah , Wyoming , Arizona , and Nevada based on field - work from the Powell expeditions . After the expedition , both Thompson and his wife returned to Aurora , Illinois . They were both listed as members of the Illinois State Association for Schoolmasters in 1873 – 1874 . In 1875 , Thompson , along with Frederick Dellenbaugh , returned to Utah focusing on field studies and mapping of the land . At the completion of their expedition assignments in 1878 , Thompson began to look for work . The April 25 , 1878 Winfield ( KS ) Courier reported that Thompson was exploring locations to start a sheep business in Kansas . The 1880 census lists Thompson is as living in Salem , Greenwood , Kansas and working as a wool grower . After the Powell Expeditions . In the early 1880s , Thompson began work for the U . S . Geological Survey under the new USGS director , John Wesley Powell . He and Ellen moved to Washington , D . C . Thompson was sent to New Mexico to begin topographical surveying . The Sundry Civil Bill of 1888 appropriated funding for an irrigation survey . Thompson directed work parties throughout the west . Later , Thompson was appointed the chief geographer for the USGS . As a geographer and cartographer , he authored or co - authored many maps for the USGS including the Green River from Union Pacific Railroad to the Mouth of the White River . Thompson was involved in a number of projects including serving as cartographer on projects in California , Colorado , Nevada , Idaho , Oregon and Wyoming . Thompson also devised a survey instrument used during geographical operations to provide measurements that could be used in determining the irrigable land . He contributed chapter IX to the " Report on the Lands of the Arid Region " , by John Powell . The chapter , titled " Irrigable Lands of the Portion of Utah Drained by the Colorado River and its Tributaries " , focuses on river drainage , tributaries , and geography . National Geographic Society . Thompson was part of a tight knit community of explorers , scientists , and businessmen in Washington , D . C . interested in forming a geographic society . He was one of several signatories on an invitation to meet on January 13 , 1888 . Thompson called the meeting to order and introduced the resolution to form the society . Within two weeks , an organizing committee consisting of Thompson and others created the plan for the National Geographic Society . Thompson was a founding member of this society . Serving as one of the vice - presidents of this new organization , Thompson was actively involved in its growth . Later years . In a report submitted July 1 , 1893 , Thompson described work conducted in all of the western states and the establishment of new field offices in California , Idaho , Oregon , and Washington . Thompson retained this post at the USGS until his death on July 31 , 1906 . He was buried at Arlington National Cemetery in the Officers Section , Site 1567 in August 1906 . Naming of geographic locations . Thompson is credited with naming many geographic locations in his work with John Wesley Powell and the USGS . He named the Waterpocket Fold in what is now Capital Reef National Park , the Aquarius Plateau , and Boulder Mountain in southern Utah , Canaan Mountain , Markagunt Plateau , Escalante River , and the town of Escalante in Garfield County , Utah . He named Mount Ellen in the Henry Mountains after his wife . Thompson had strong opinions about the need for principles to aid in geographic nomenclature . He stated that " a geographic name should be short , euphonic , pronounced as spelled , and have a meaning or express some sentiment to help fix it in the memory " . In choosing geographic names during the Powell expeditions , Thompson selected a combination of Piute terms such as Kaibab and Toroweap , Mormon pioneer words like Pipe Springs and Wild Band Pockets , and also used descriptive words like Tantalus Creek and Thousand Lakes Mountain . Thompson Mesa in the Henry Mountains , Thompson Point in the Grand Canyon Mount Thompson in the Sierra Nevada Mountains , and Thompson Peak in the Sangre de Cristo Mountains near Santa Fe were all named in honor of A . H . Thompson . Legacy . Thompson ' s accomplishments are often overlooked in history books and websites . Dellenbaugh notes that although Thompson was largely responsible for the " scientific and practical success of the second expedition " , Powell ignored Thompson ' s contributions in his reports . In the introduction to Thompson ' s diaries , Herbert Gregory states that " Thompson possessed that rare combination of qualities that brings success to the explorer : a rigid insistence on discipline and order of procedure , kindness toward his subordinates , and sympathetic interest in the native people with whom he came in contact " . Frederick Dellenbaugh , author of The Romance of the Colorado River and member of the expedition , stated that " to his ( Thompson ' s ) foresight , rare good judgment , ability to think out a plan to the last minute detail , fine nerve and absolute lack of any kind of foolishness , together with a wide knowledge and intelligence , this expedition , and indeed the scientific work so admirably carried on by the United States Survey of the Rocky Mountain region and the Geological Survey for three decades in the Far West , largely own success " .