The Dominion Land Survey (DLS) is a ground-surveyed grid of square-mile sections used across Alberta, Saskatchewan, Manitoba and BC’s Peace River Block. The National Topographic System (NTS/BCGS) is a pure latitude-longitude graticule used for well and land locations across the rest of British Columbia. The quickest tell: a DLS description ends in a meridian like W4, while an NTS location has a slash in the middle, like d-96-H/94-A-15.
Side-by-side comparison
DLS
NTS / BCGS
Origin
Dominion Land Survey, laid out on the ground for prairie settlement from 1871
National Topographic System map-sheet grid, subdivided on paper from latitude and longitude
Geometry
Physical monuments; imperial units (miles and acres); jogs at correction lines
Mathematical graticule; cells defined in degrees, minutes and seconds; no monuments needed
Largest cell
Township: ~6 × 6 miles, 36 sections
Primary quadrangle (e.g. 94): 8° of longitude × 4° of latitude
Smallest cell
Legal subdivision (LSD): 40 acres, 16 per section
Quarter unit (a/b/c/d): a quarter of a 45″ × 30″ unit
Where used
Alberta, Saskatchewan, Manitoba, and BC’s Peace River Block
British Columbia outside the Peace River Block — especially oil & gas well locations
Format
4-12-52-24-W4, NE-14-48-1-W5
d-96-H/94-A-15, A-1-J/93-P-8
Worked example: one of each
Both systems read from the smallest cell to the largest, but the pieces mean very different things.
In 1883 British Columbia transferred a block of land in the Peace River country to the federal government as part of the railway agreements, and Ottawa surveyed it with the same Dominion Land Survey system it was using on the prairies. That is why farmland around Dawson Creek and Fort St. John carries prairie-style descriptions — sections, townships and ranges west of the Sixth Meridian (118°W) — while a wellsite an hour north uses NTS.
The rest of the province was never covered by the DLS grid — the terrain made a monument-based square-mile survey impractical. So when BC needed a systematic way to identify oil and gas well locations, it adopted a grid derived from the National Topographic System map sheets instead, formalized in the Petroleum and Natural Gas Grid Regulation (B.C. Reg. 536/2004). BCGS (the BC Geographic System) applies the same graticule logic to the province’s 1:20,000 mapping.
How to tell which system a string is
Ends with a meridian?W4, W5, W6, W2, E1— it’s DLS.
Contains a slash? The /separates the quarter-unit-block part from the map sheet — it’s NTS/BCGS.
Starts with a single lowercase letter a–d (or A–D in some records) followed by a number up to 100 — NTS/BCGS.
Starts with a quarter like NE/NW/SE/SW, a half like WH/EH, or an LSD number 1–16 — DLS.
All numeric groups plus one trailing meridian, e.g. 19-17-26-W2 — DLS at section level.
Coverage and limitations
This site converts DLS descriptions for Alberta, Saskatchewan, Manitoba and the BC Peace River Block using more than 21,000 townships of surveyed corner coordinates from provincial records, and NTS/BCGS locations across British Columbia using exact graticule math. In northeast BC the officially published NAD83 grid corners can differ from the ideal graticule by up to about 100 m. Results are navigation and reference grade — not a legal survey. See coverage for supported formats and provinces.
Both systems, offline, in one app
Land Description Lookup for iPhone converts DLS, LSD and BC NTS locations entirely on-device — with offline base maps, current-location lookup and field navigation, kilometres from the nearest signal.
DLS positions are computed from surveyed township corners published by the governments of Alberta (ATS/AltaLIS), Saskatchewan (ISC SaskGrid), Manitoba and the BC Energy Regulator. NTS/BCGS positions follow the Petroleum and Natural Gas Grid Regulation (B.C. Reg. 536/2004). Read the full methodology.
