[Map with Report] Soil Map Napa Area California [with] Soil Survey of the Napa Area, California: U.S. Department of Agriculture | Bureau of Chemistry and Soils, 1938

• Title: [Map with Report] Soil Map Napa Area California [with] Soil Survey of the Napa Area, California published by E.J. Carpenter (United States Department of Agriculture, in Charge)
• Author: U.S. Department of Agriculture | Bureau of Chemistry and Soils | Henry G. Knight, Chief
  
• Date: 1938
• Condition: See Description
• Inches: 33 1/4 x 40 3/8 [Paper] 
• Centimeters: 84.45 x 102.55 [Paper]
• Product ID: 308634

Napa’s Hidden Terroir: The Rare Soil Map That Predicted a Wine Empire

This large folding map depicts Napa Valley in exceptional detail at a scale of one inch to the mile, extending from Calistoga in the north to Napa in the south. Issued just as Prohibition ended, it captures the valley at the moment when its wine industry was beginning to revive. Finely engraved and beautifully colored, it delineates every town and village, roads and railroads, and even individual buildings, including Stags Leap Manor, Zinfandel, Oak Knoll, Rutherford, Myrtledale Hot Springs, Pacific Union College, and many other landmarks.

An impressive sixty-four distinct geological types are distinguished by separate colors and patterns, and an expansive legend identifies a wide range of physical features. The map is issued with the 76-page report “Soil Survey of the Napa Area, California,” in printed paper wrappers, both now neatly rebound in a modern library binding with the map housed in a rear pocket, hardbound in blue cloth with a gilt title on the spine.

Napa Valley in the 1930s

In the 1930s, Napa Valley was emerging from the combined shocks of phylloxera, the Great Depression, and Prohibition, so viticulture and winemaking remained relatively subdued and economically fragile. With the repeal of Prohibition in 1933, a slow recovery began as a limited number of wineries—such as Inglenook, Beaulieu Vineyard, Louis M. Martini, and Charles Krug under new ownership—restarted or expanded operations, though overall production and profitability stayed modest through the decade. Promotional materials from the era tended to emphasize the region’s mild climate, general agriculture, mineral springs, and outdoor recreation rather than wine, reflecting both lingering Prohibition-era attitudes and the still‑rebuilding state of the wine industry.

Condition 

The folding map itself is notably clean and vividly colored, bearing only an old library stamp in the lower blank margin. The accompanying text remains bright and legible, with some earlier library notations visible on the front wrapper. The modern library binding shows minimal signs of use and includes a “discard” stamp on the front endpaper.

Rarity

Of the Utmost Rarity. The book report is the only known example EVER made available to the market.

Background on Creator

The U.S. Department of Agriculture produces a wide range of thematic and statistical maps that visualize crop production, livestock distribution, land use, irrigation, drought impacts, and other key agricultural conditions across the United States. These maps often combine Census of Agriculture data with current monitoring information—such as drought status or crop progress—to support policy decisions, risk management, conservation planning, and farmer outreach. Over the 20th century, USDA and its predecessor bureaus built up a substantial cartographic record, creating national and regional maps that depict farming regions, land classification, water resources, and economic patterns in agriculture.