The Squares

When you first look at a topo map you’ll notice there are lots and lots of squares. Look closer and you’ll find letters and numbers written across the top and bottom of the map and inside some of the squares. Let’s start with the smallest squares first.

I.   Sections

A section is a square tract of land that measures one mile by one mile and contains 640 acres. There are 36 sections in a township, but not all the sections may be numbered on a topo map. Sections are also numbered kind of strangely, starting in the uppermost right corner with the number 1 and then moving to the left six squares, down one square, right six squares. The reason for numbering sections this way is so there will never be two sections with the same number next to each other in adjacent townships.

*Note: Only the bold numbers (1,6,31,36) are usually on a BLM 1:100,000 map.