How to use survey info to identify locations in the forest.

The United States is made up of townships that are 6 miles square, or 36 square miles, with each section numbered starting at the upper right in the manner shown in the illustration. The north/south orientation has a township number and the east/west orientation is called the range, and is also numbered.

The corners of these square mile sections have been surveyed and marked throughout the forest. Before the advent of Global Positioning Systems, these corners were used to identify property lines for stumpage or land sales.

The illustrations and maps used in this lens are for the Chippewa National Forest in northern Minnesota.

The marker tells us we are at the corner of sections 21 and 22 and 27 and 28, and the township is 150 North and the range is 27 West. The photo shows where this marker is located on a USGS 7.5 minute quadrangle map. You can see the section lines and where they intersect at the south end of Glove Lake, the spot is about where the cartographers decided to print the elevation.

There are generally four base trees marked near a corner monument. The base trees will have big red blazes at eye level on one side of a tree, the corner will be inside the area marked by these blazes on all four trees. Very often, the letters B/T are also painted on the tree to indicate it is a base tree. Base trees are not a certainty though, as trees may blow down, rot, burn, etc.

Although often placed on posts, these information tags could be simply tacked to a tree, usually at eye height. However, you have to know that with the advent of GPS technology, these markers started losing their value and they are disappearing.