Canada 1:250,000 Topographic Map Index

Steven Dutch, Professor Emeritus, Natural and Applied Sciences, University of Wisconsin - Green Bay

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Place the cursor in the desired map quadrangle to read the name.

The numbering system works as follows:

• The first two digits are the longitude of an 8-degree zone, starting with 01 for 48 to 56W and ending with 12 for 136 to 144 W. East longitude of zone = 40+8*Zone index
• The third digit is for 4-degree latitude zones, starting with 1 for 44 to 48 N and ending with 9 for 76 to 80 N. South latitude of zone = 40+4*Zone Index
• North of 80N, 120 is used for longitude 56-72 W, 340 for 72-88W and 560 for 88-104W. 120 corresponds to longitude zones 10 and 20, and so on.
• South of latitude 68, blocks 2 degrees wide by one degree high are lettered starting with A in the southeast and zigzagging to P in the northeast. From north to south and west to east, the letters run M,N,O,P; L,K,J,I; E,F,G,H, and D,C,B,A.
• From 68 to 80 N (second digit 7, 8, or 9), blocks 4 degrees wide by 1 degree high are lettered, zigzagging from A in the southeast to H in the northeast.
• Above 80 N, blocks 8 degrees wide by 1 degree high are lettered, zigzagging from A in the southeast to H in the northeast.