Topographical map of the road from Missouri to Oregon, commencing at the mouth of the Kansas in the Missouri River and ending at the mouth of the Wallah Wallah in the Columbia, in VII sections : from the field notes and journal of Capt. J.C. Fremont, and from sketches and notes made on the ground by his assistant Charles Preuss ; compiled by Charles Preuss, 1846, by order of the Senate of the United States

First issue of the first map "to show the Oregon Trail accurately with great detail" (Rumsey); "An extraordinary map by a master cartographer" (Graff). "Used by many of the overland trail parties, and published only three years before the gold rush, it was based on the 1,670 mile journey of 1842-3 lead by John Charles Fremont, from the Missouri to the Columbia Rivers, by the cartographer Charles Preuss. "This valuable overland guide map must not be confused with those found in Fremont’s reports. Preuss was topographer on the "Pathfinder’s" first Fremont expedition and herein records the daily stopping places with notes on the country, water, wood, game, Indians, and other subjects of interest or reasons for caution along the way. Each of the seven map-sections has its own separate title together with observations and extracts from Fremont’s Report relevant to the portion of the route depicted." One of the observations pertains to the Great Salt Lake: "one of the wonders of nature, and perhaps without a rival in the world". There was a second issue of this map, contained in the 1849 Rockwell report. This is the original 1846 separate issue, with the lithographer's imprint (E. Weber & Co., Baltimore) present, sheets III and VI properly numbered, etc. The maps follow the following route - Section I: Kansas; Section II, Nebraska; Section VI (i.e. Section III) Nebraska & Wyoming; Section IV Wyoming & Idaho; Section V Wyoming & Idaho; Section III (i.e. Section VI): Idaho; Section VII: Idaho, Oregon & Washington. Seven uncolored lithographed sheets bound together at the right margin. The sheets are bright and clean, in remarkably good condition with two old folds, one horizontal & one vertical. With a light water mark at the bottom right hinge, only lightly affecting a couple of images. At some stage, a diagonal slit traversing the verso of the first three sheets has been expertly repaired with Japanese tissue paper, so well done that it is barely detectable on the front. The fourth sheet has an "L" shaped repair from the left margin to the center fold. A couple of small hole repairs to verso of last sheet; some intermittent light water stains at the horizontal fold. All faults mentioned do not detract from this highly desirable, very nice copy. 26 3/8 x 16 ", bound on the right margin with green paper, as issued. Wheat 523, Rumsey 2773.001-.007, Streeter Sale 3100, Wagner-Camp 115, note.…