Milk River to the Crossing of the Columbia River

The northern section of the Pacific Railroad Survey.

This fascinating mid-19th century map shows a broad territory along the 47th parallel between Fort Benton (Montana) on the Missouri River and Fort Walla Walla (Washington) on the Columbia River. It presents the results of the Northern Pacific railroad survey led by the governor of the Washington Territory, Isaac Stevens, between 1853 and 1855. Among Steven’s party was Captain George B. McClellan, future general of the Union Army.

The survey was one of five that were conducted under the direction of Secretary of War Jefferson Davis to determine the most desirable route for a transcontinental railroad across America. These various expeditions quite literally ‘opened up’ the West for future settlement in the years following the California Gold Rush and were among the first federally-sponsored explorations in their respective regions. Accompanying scientists also made valuable discoveries in the fields of geology, botany, biology, anthropology, and paleontology.

The image shows the routes undertaken by various parties under Steven’s command, each dated to highlight the progression of the survey across different seasons. Topography is depicted with contours, providing a dramatic overview of the rugged terrain and various geographic features. Many, such as the Continental Divide, Lewis & Clark’s Pass, and the Bitterroot Mountains, are labeled; along with scattered missions, forts, Indian agencies, and trading posts.

Published in Washington, D.C. in 1859 by the Government Printing Office as part of a congressional report for the U.S. House of Representatives.

Sources: Wheat #867; Eastern Washington University; Stanford University Library