About this site
Michigan Lake Depths publishes depth maps for 2,148 Michigan lakes across 81 counties, built from public Michigan DNR survey data. This page explains who runs it, where the data comes from, and what it should not be used for.
Who publishes it
Michigan Lake Depths is published by Jay Goklani through Goklani Advisory LLC. It is an independent project, built and maintained by one person.
This site is not affiliated with Michigan DNR, or with any state or federal agency. It is not an official source. The underlying survey data is public government data, used and credited as such; the maps, writing, and analysis on this site are its own.
Where the data comes from
Every lake page names its own sources, because they differ from lake to lake. Across the site they are:
- Michigan DNR lake contours — the survey-derived depth contours the maps are built from. A contour is a line joining points of equal depth, drawn from a survey's soundings; it is not itself a sounding, and the deepest contour on a map is not necessarily the deepest point of the lake.
- USGS 3DEP — land elevation surrounding each lake.
- USDA NAIP — public-domain aerial imagery.
- OpenStreetMap (ODbL) — shorelines, roads, and place names.
How the maps are made, and their limits
Surveyed depth contours are interpolated into a continuous basin and draped over real land elevation. Depth between the surveyed contours is estimated, not measured. Where a survey stopped short of a lake’s own reported maximum depth, the page says so rather than implying the deeper water was mapped.
Surveys are historical. Lake beds shift, water levels change, and hazards are not charted. These maps are reference material and must not be used for navigation or boating safety.
What happens when the data is missing
Lake records are matched conservatively. Where a lake cannot be confidently matched to a survey, a fish record, or a public access site, the page says the information is unavailable — it does not report an absence of data as an absence of fish, of depth, or of access. A handful of lakes hold only a shoreline outline with no usable soundings, and those say exactly that instead of showing a depth of zero.
How it is funded
The site is supported by advertising sold directly. There are no ad networks or cross-site advertising trackers. We use aggregate site analytics to understand traffic and improve the project; advertisers do not receive visitor-level data. Advertisers have no influence over lake data or what any page says.
Corrections
Corrections are genuinely welcome, particularly from the lake associations, watershed groups, and agency staff who know these waters far better than any dataset does. Every lake page carries a correction link, or write directly: