Tornado Belt Maps

 

Pre-1887 U.S. Tornado Belt
Pre-1887 U.S. Tornado Belt

“…that part of the state north of 46° 30′ is practically exempt from tornadoes…” 
Monthly Weather Review, April 1886, page 113.

 

 

Pre-1887 Northern Pacific Railroad Tornado Belt
Pre-1887 Northern Pacific Railroad Tornado Belt, Adapted from Library of Congress Northern Pacific Railway Map, 1900

The northern limit of tornadoes is “…north of the main line of the Northern Pacific Railway”,
which extends from Duluth to Brainerd, Minnesota, then to Fargo, Dakota Territory. 
Monthly Weather Review, April 1886, page 113.