National Topographic System

[1] These maps are currently used by all levels of government and industry for forest fire and flood control (as well as other environmental issues), depiction of crop areas, right-of-way, real estate planning, development of natural resources and highway planning.

This scheme initially splits the country into three major "zones", each spanning a different range of latitudes.

In the Southern and Arctic zones, the National Tiling System numbers map series by latitude and longitude.

In the High Arctic zone, map series numbers are three digits, with the first two digits of each number inherited from the two map series in the Arctic zone immediately to the south.

"Military Town Plans" were also prepared on the same 1:25,000 scale, with "declassified versions" available to the public; the classified versions had places of military significance marked; these maps did not follow a quadrangle plan of any kind.