The lot is composed of the titled map and original report with plates. In the early 1870's, Lt. General Sheridan ordered Forsyth and Grant to explore the region along the Yellowstone River in eastern Montana to collect information for future military operations against the Plains Indians. Starting at the mouth of the Yellowstone River at the Missouri, Forsyth and Grant traveled up the river on the steamboat Josephine noting river conditions, terrain, timber resources, game, Indian sightings, and the occasional geological observation. The expedition succeeded in advancing up the Yellowstone to a point west of Pompey's Pillar (the famous Lewis and Clark landmark), where river conditions thwarted further advancement. Today this section of the river is followed by Interstate 94 from below Miles City to Billings. The expedition is also notable for taking place only a few months before the Custer disaster at the Little Big Horn. The five plates show the mouth of Powder River, Castle Rocks, and a map of Pryor's Creek. The large folding map shows about 250 miles of river course with topographical details, navigation hazards, and other observations. Wheat spends nearly a full page on this "unusual" map. In particular he quotes many of the "interesting marginal annotations" presented on the map. The map was drawn by 2nd Lt. Richard E. Thompson, 6th Infantry. Map is bound in original 18 pp report with plates.

References: Wheat (TMW) #1253.

Condition: A+

Remarkable condition for a large folding map with just two tiny tears at binding trim. Front page of report has a little foxing at upper left and owners signature above title. Contents are flawless. Report is disbound.