1964 USDA Hardiness Zone Map

1964 USDA Hardiness Zone Map

Thanks to George Andrykovitch for forwarding me a copy of this map. As far as I can tell, the USDA no longer carries a copy of "U.S. Department of Agriculture. 1972. Plant hardiness zone map. USDA-ARS Misc. Publ. No. 847". Here is an alternate, larger, black and white version that I found in "Selecting Shrubs for Shady Areas" (Michigan State University).