Minnesota used the U.S. Public Land Survey System to identify the survey areas to be covered during the Atlas.
The Public Land Survey System is based on a 36 square mile area called a township. Townships are subdivided into 36 sections (each 1 mile by 1 mile).
U.S. Public Land Survey Township
Priority Blocks
To reduce survey bias, the Minnesota BBA randomly selected the NE quadrant (3 miles by 3 miles) of every township in the state to survey. These selected areas are called Priority Blocks. In cases where the NE quadrant was not complete, we selected the SE quadrant or continued clockwise to select a complete quadrant. If the township had no complete quadrants, the township was excluded from the MNBBA. There are 2352 Priority Blocks to be surveyed during the Atlas project.
Secondary Blocks
Secondary blocks (quadrants in the township outside the Priority Block) may also be surveyed where a habitat type in the township is under-represented in the Priority Block or when special sites do not fall within the Priority Block. Special sites include National Wildlife Refuges, State Parks, State Scientific and Natural Areas or Important Bird Areas. Regional Coordinators can help surveyors identify these special sites.
Block IDs
Blocks are identified by a township and range number plus a one-letter code that describes whether the block is the NE (a), SE (b), SW (c), or NW (d) quadrant in the township. For example, a block labeled T123R15a is in Township 123N, Range 15W, the NE quadrant of the township.
Don't hold back - you can 'own' more than one block! Remember, we need to cover all 2352 Priority Blocks to complete the Atlas.
Ready to browse to Request Block in your area?