In 1849, officials of the US Army Corps of Topographical Engineers sent Captain Howard Stansbury and his assistant Liuetenant John Williams Gunnison on a two-year expedition to explore and survey the Great Salt Lake Valley. While the area was not unknown — indeed a major influx of Mormon settlers had already taken place — the end of of the Mexican-America War in 1848 and the massive new western areas gained by the United States, spurned a new era of scientific mapping there.
The map constitutes a comprehensive survey of the Great Salt Lake, the Jordan River, and Utah Lake. It follows the valley, extending north beyond the lake to modern-day Logan and Highway 84 (which follows the same line as the “Emigrant Road” marked on the map) and south beyond Provo (labeled “Utah Settlements”) to Mt. Nebo. It includes town plans and plots for Salt Lake City and Ogden.
In order to complete this ambitious project, Stansbury and Gunnison divided the task. In October 1849, Stansbury undertook a four-week circumnavigation by land of the Great Salt Lake, starting with the most daunting western section first, which was largely inhospitable desert. Meanwhile, Gunnison surveyed the territory to the south including Utah Lake. The winter of 1850 was particularly harsh, and the engineers were lucky to be assisted by the local Mormon settlers, who became important allies to the expedition. The team constructed triangulation stations and accumulated a massive amount of cartographic data.
The map appeared in Stansbury’s account of his travels, Exploration and Survey of the Valley of the Great Salt Lake of Utah, including a Reconnoissance of a new Route through the Rocky Mountains, which was first issued as a Senate document. The expert topographer Charles Preuss helped create the final maps.
Overall, this was the definitive map of the Great Salt Lake of its time and an essential document reflecting a new understanding of the area.