Clason’s Guide Map of the State of Idaho

WWI-era road guide to Idaho.

This finely detailed map of Idaho was copyrighted in 1916 by the Clason Map Company of Denver, Colorado. During the early 20th century, Clason specialized in high-quality guides for the burgeoning Western automobile tourist, capturing the region just as the “Auto Trail” movement began to standardize travel across the Continental Divide. The base map provides a sophisticated structural framework of the “Gem State,” delineating county and township boundaries, intricate waterways, and a diverse array of settlements.

Vibrant green overprinting identifies the expansive National Forest reserves that dominate the Idaho Panhandle and central mountains. Of particular interest is the vibrant red overprinting used to designate the state’s nascent road network. Bold lines identify major Transcontinental Routes, including the recently organized Yellowstone Trail (1912) and the “rebranded” Oregon Trail, while thinner lines represent more localized wagon roads and trails.

This example is accompanied by its original 32-page descriptive index, a comprehensive geographic census offering mileage tables, topographical data, and population statistics for even the smallest mining and timber communities. The map stands as a premier document of the “Good Roads” era, published a decade before the federal government replaced these named trails with the standardized U.S. Highway System in 1926