A H. 1839-1906 Thompson

Almon Harris Thompson (1839-1906) was an American explorer, cartographer, and topographer best known for his participation in John Wesley Powell's expeditions to map the Colorado River and the American Southwest in the 1870s. After a brief Civil War service, he began his career as a school superintendent in Illinois in 1864 before joining Powell's surveys. His detailed diaries and maps from these expeditions remain significant historical records of the region's exploration.