A third system that is used in both state and federal land states refers to a lot number on a plan for a subdivision. Depending where you live in the U.S., it might be called the recorded plat, recorded map, recorded survey or the lot-block-tract system. Briefly, a map of a large tract of land has been surveyed into smaller lots, the subdivision named and the new lots numbered. Then the resulting map is recorded at a county land records office. From that time, a legal description of one of the small lots can just refer to the number on the recorded map.You might think this seems like a modern suburban subdivision which it is. If you think that you would not be able to find an older deed that uses this method to describe land, you would be wrong. I have found a deed from 1843 in Massachusetts and 1850s Pennsylvania. So be ready.
Here is an example from a turn of the 20th century Montana deed:
Necessary information:Name of subdivision: Seymer Park Addition, Block 17, City of Helena
Lot Number(s): 1,2,3
Where map recorded: Office of the Clerk and Recorder, Lewis and Clark County