A lake depth contour map is a drawing of a lake seen from above, with lines that connect points of equal depth below the water. Read from the shoreline inward, each ring marks a step deeper, so the lines show the shape of the basin the way a hiking map shows the shape of a hill. Our prints turn those lines into wall art and keepsakes for people who know a particular lake by heart.
How the lines work
Think of filling a lake bowl one layer at a time. The shoreline is the zero line. The next line traces everywhere the water is, say, five feet deep, the next line everywhere it is ten feet deep, and so on until the rings close around the deepest hole. The fixed step between rings is called the contour interval.
Two simple rules make any contour map readable:
- Lines close together mean the bottom drops quickly, as along a steep shore or the side of a deep hole.
- Lines far apart mean the bottom slopes gently, as across a broad shallow bay or a flat basin floor.
- Small closed rings in the middle of a lake mark a separate hole or, read the other way, a rise such as a hump or an island shoal.
Once you can see those patterns, a familiar lake starts to look different on paper. The drop-off off the dock, the shallow weedy end, the point where the water turns dark: they all show up as lines.
Where our lake contours come from
The outlines and depth contours on our Michigan maps come from Michigan Department of Natural Resources lake survey maps. Those surveys go back a long way. A 1939 report from the state’s Institute for Fisheries Research describes crews mapping lakes in winter, drilling holes through the ice and taking depth soundings with a weighted, calibrated line, then tracing shorelines from enlarged aerial photographs. The report notes that mapping through the ice was found to be more reliable than working from a boat in summer.
We clean up and redraw that survey linework for print. You can read more about the process on our how the maps are made page, and the history of the source maps in our post on the Michigan DNR lake survey maps.
Two numbers we list for each lake
Most lake pages on this site show two figures taken from the survey data: the lake’s maximum depth and the number of contour lines in its map. They describe different things, and the second one is the better guide to how a print will look.
Maximum depth
This is the deepest point recorded on the survey map. Among the lakes with figures on our site, Lake Angeline in Marquette County is the deepest at 162 feet, followed closely by Syphon Lake in Luce County at 160 feet. Many lakes on the site sit somewhere between 20 and 50 feet.
Contour lines
This is a count of the depth lines in the map data, and it shapes the look of the design more than depth does. A deep lake does not always have the most lines. Lake Angeline carries 52 contour lines in our data, while Trout Lake in Alger County has a maximum depth of only 11 feet yet carries 65 lines, the most of any lake on the site. A lake with many small holes, bars and bays can produce more linework than a deep, simple bowl.
At the other end, Fawn Lake in Schoolcraft County reaches 33 feet with just 5 contour lines. Prints of lakes like that read as a few bold, calm rings rather than a dense pattern.
What a contour map is not
Our prints are decorative. The source surveys are decades old in many cases, lake levels change, and bottoms shift. The DNR itself notes that its lake maps may not represent current conditions. Please do not use a gift print, a mug or a T-shirt to judge water depth for boating, swimming, diving or ice travel. For anything on the water, rely on current official information and local knowledge.
Why contour maps make good gifts
People who love a lake tend to know it in pieces: the sandbar where the kids played, the deep spot off the point, the cove that freezes first. A contour map puts those pieces together in one picture they can recognize at a glance, even without a label.
Every lake on the site comes in a minimal contour design in light and dark versions plus a shaded depth-map print, made to order by CafePress on T-shirts, hoodies, mugs, posters, canvas prints, stickers and postcards. Lake pages show a starting price for each product; the final price, any sales and shipping are shown at checkout.
To find a lake, start with our Michigan lake index or browse by area on the Upper Peninsula region page. If you are unsure which design to choose, our FAQ answers the common questions.
Frequently asked questions
What does a contour line on a lake map mean?
It connects points that are the same depth below the water surface. Each line inward from the shore marks a step deeper, and the space between lines shows how quickly the bottom drops.
Is a depth contour map the same as a bathymetric map?
Yes, in everyday use. Bathymetry is the measurement of underwater depth, and a lake contour map is one common way of drawing it.
Can I use your lake map for fishing or boating?
No. Our prints are decorative and based on older survey data. Use current official charts and local guidance for anything on the water.
Why do some shallow lakes have more lines than deep ones?
The line count reflects the shape of the basin as well as its depth. A lake with many separate holes and bays can produce more contour lines than a deep, bowl-shaped lake.