Salt Lake City, Utah, May 27, 1870. Single sheet (integral leaf likely perished), 10 x 7 3/4 in. (254 x 197 mm). One-page autograph letter, signed by Brigham Young to "Elder Thomas Collister, Bishop of Fillmore and the bishops of the various settlements between that city and St. George", allowing passage for botanist Dr. Edward Palmer of the Smithsonian Institute, then "on his way to St. George, from which place he purposes starting on a scientific exploration of northern Arizona and the country contiguous" and requesting that they "afford Dr Palmer all the aid and information in your power, to enable him to successfully accomplish the objects of the expedition." Creasing from old folds.

Edward Palmer (1829-1911) was a British-born botanist and early-American archaeologist. Employed by the Department of Agriculture and the Smithsonian Institute, he is considered the "father of ethnobotany". During his career he established frameworks, still in use today, for the collection and reporting on plant specimens, which he extensively collected throughout North and South America.