How LSD numbering works

The serpentine rule is worth memorizing because it is not what most people guess: the numbers do not read left-to-right like a book, and they do not start in the northwest. Start at the southeast corner, sweep west, and reverse direction at the end of each row. The odd-looking consequence is that the first and last LSDs share the east edge — LSD 1 in the southeast corner, LSD 16 in the northeast — and vertically adjacent LSDs can differ by as much as 7 (LSD 8 sits directly above LSD 1).

Worked example: 4-12-52-24-W4

Reading 4-12-52-24-W4 from the right: west of the 4th meridian (110°W), range 24, township 52, section 12 — a square mile in southeast Edmonton whose centre is at 53.476038, -113.405612. The leading 4picks LSD 4 from the grid above: the bottom-left cell, i.e. the 40 acres in the section's southwest corner. This is the format Alberta oil and gas well locations use, which is why an LSD is often the first thing a landowner, surface-rights holder or field operator is handed.

For what the rest of the description means, see how to read a legal land description and township, range and meridian explained.

How LSDs relate to quarter sections

A quarter section (160 acres) is exactly four LSDs in a 2×2 block, and the LSD grid lines up with the quarter boundaries — the heavier lines in the diagram above. Because the numbering snakes rather than reading in rows, each quarter's four LSDs are not consecutive:

This mapping is handy in both directions: if a well licence says LSD 7, you know it sits on the southeast quarter; if a land agent says “the northwest quarter,” the candidate LSDs are 11 through 14. Our example LSD 4 falls in the southwest quarter, so 4-12-52-24-W4 lies within SW-12-52-24-W4.

Sections snake the same way

The serpentine idea repeats one level up. A township's 36 sections are numbered boustrophedon — “as the ox ploughs” — from the southeast corner: 1–6 run west along the bottom tier, 7–12 double back east, and so on until section 36 lands in the northeast corner.

Note the one difference between the two grids: sections start their serpentine going west from 1 in the southeast, exactly like LSDs, but there are 36 of them in six rows instead of 16 in four. How townships themselves are numbered is covered in township, range and meridian explained.

Coverage and limitations

• The LSD mapping system applies across Alberta, Saskatchewan and Manitoba, and in BC's Peace River Block. Elsewhere in British Columbia, well locations use the NTS/BCGS system — see DLS vs NTS.
• The diagrams above show the idealized grid. On the ground, section and LSD boundaries follow the original survey monuments, so this site computes positions from roughly 21,000 townships of surveyed corner coordinates rather than pure grid math.
• Coordinates are for navigation and reference only. They are not legal land-survey records and cannot substitute for a survey by a licensed land surveyor.