John Williams Gunnison (November 11, 1812 – October 26, 1853) was an American military officer and explorer. Biography Gunnison was born in Goshen, New Hampshire, in 1812 and attended Hopkinton Academy in Hopkinton, New Hampshire. He graduated from West Point in 1837, second in his class of fifty cadets. His military career began as an artillery officer in Florida, where he spent a year in the campaign against the Seminoles. Due to his poor health he was reassigned to the U.S. Army Corps of Topographical Engineers the next year. Initially he explored unknown areas of Florida, searching for provision routes. However, his health soon forced him out of Florida entirely. From 1841-1849 Gunnison explored the area around the Great Lakes. He surveyed the border between Wisconsin and Michigan, the western coast of Lake Michigan, and the coast of Lake Erie. On May 9, 1846, he was promoted to first lieutenant. In the spring of 1849 Gunnison was assigned as second in command of the Howard Stansbury expedition to explore and survey the valley of the Great Salt Lake. That winter was particularly heavy and the expedition was unable to leave the valley. Gunnison took the opportunity to befriend some Mormons and study the Church of Jesus Christ of Latter-day Saints. When he finally returned to Washington, DC, he wrote a book titled The Mormons or Latter-Day Saints, in the Valley of the Great Salt Lake: A History of Their Rise and Progress, Peculiar Doctrines, Present Condition. Gunnison returned to the Great Lakes from 1851–1853, mapping the Green Bay area, and was promoted to captain on March 3, 1853. Gunnison–Beckwith expedition On May 3, 1853, he received orders to take charge of an expedition to survey a route for a Pacific railroad between the 38th and 39th parallels. The surveying party left St. Louis, Missouri, in June 1853 and arrived by mid-October in Manti, Utah Territory. In Utah Territory, with Lieutenant E. G. Beckwith as assistant commander, Gunnison began the survey of a possible route, surveying areas across the Rocky Mountains via the Huerfano River, through Cochetopa Pass, and by way of the present Gunnison and Green rivers to the Sevier River. His journey took him through the Tomichi Valley in Colorado, where the town of Gunnison is named in his honor. After crossing the Tomichi Valley, the survey team encountered the Black Canyon, carved by the Gunnison River which was