The Federal Aid Highway System progress map : [Minnesota]
United States. Bureau of Public Roads. Geological Survey (U.S.)
Cartographic Details: Scale 1:500,000 ; Modified polyconic projection (W 97‚Å∞15 π--W 89‚Å∞30 π/N 49‚Å∞23 π--N 43‚Å∞30 π). Sheets numbered 23NE, 23NW, 23SE, and 23SW. Base map from U.S. Geological Survey state map. "Published in accordance with Act of Congress approved Nov. 9, 1921, creating the Federal Aid Highway System. Data corrected to July 1, 1933." Contents: Northeastern Minnesota -- Northwestern Minnesota -- Southeastern Minnesota -- Southwestern Minnesota.