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Indiana lake depth maps

Riddles Lake depth map

Riddles Lake in St. Joseph County, Indiana reaches a depth of 18 feet. Riddles Lake is charted here across 6 closed depth contours, from the 3 ft line down to 18 ft, enclosing about 64 acres of water. Half of that water lies inside the 12 ft line, and only 1.5 acres lie inside the deepest one. Every contour is on the interactive map below, free and without an account.

Data: Indiana DNR Lake Bathymetry (credit: Indiana DNR). Contours closed, checked and area-computed by Jordan Carter, founder of GilledIt · page updated

Riddles Lake depth chart: 6 depth contours from 3 to 18 ft

Data: Indiana DNR Lake Bathymetry (credit: Indiana DNR), retrieved August 2026 · depths change over time · not for navigation

Riddles Lake depth chart data: water enclosed by each contour
Depth contourWater inside itShare of mapped water
3 ft64 acres100%
6 ft49 acres75%
9 ft33 acres51%
12 ft20 acres31%
15 ft8.8 acres14%
18 ft1.5 acres2.3%

Acreages are computed from the closed Indiana DNR Lake Bathymetry contour rings, with islands subtracted. Shares are of the 64 acres inside the outermost charted contour (the 3 ft line), which is the outer edge of the mapped water, several state files carry no 0 ft shoreline line, so this is not the same as a share of the lake's published surface area.

Fishing Riddles Lake: steep sides for its size

The survey encloses about 64 acres of Riddles Lake inside its 3 ft contour, and half of that water lies inside the 12 ft line, so the bottom holds its depth well out from the bank rather than tapering off a long shallow margin. Between 6 and 9 ft the mapped water sheds 16 acres in 3 ft of depth, the sharpest change on the chart, start on that band, because it is where the bottom stops being flat. 1.5 acres, 2.3% of the mapped water, lie inside the deepest 18 ft contour, toward the northwestern corner of the lake. Topping out at 18 ft, weed growth structures this water more than depth does, but the 1.5-acre deep spot still concentrates fish in the heat of summer, and the one-contour depressions on the chart are the ones most anglers row straight over.

Ice fishing on Riddles Lake

A shallow lake like Riddles Lake is usually among the first to make safe ice, and once the weed beds die back the fish have very little deep water to spread into: just 1.5 acres inside the 18 ft contour. Start there, then hunt the subtle single-contour depressions across the 64-acre basin. Check ice thickness locally before you walk out.

Riddles Lake depth map FAQs

How deep is Riddles Lake?
Riddles Lake reaches a maximum depth of 18 feet in the Indiana DNR Lake Bathymetry survey. Most of it is far shallower: the survey charts 6 closed depth contours over about 64 acres, and half of that water sits inside the 12 ft line.
Where is the deepest part of Riddles Lake?
The deepest charted water on Riddles Lake lies inside the 18 ft contour, toward the northwestern corner of the lake. That contour encloses 1.5 acres, 2.3% of the mapped water, so it is a small target on a small water, the depth chart above gives the contour to line up on.
How much of Riddles Lake is shallower than 12 feet?
About half. The 12 ft contour encloses 20 acres of the roughly 64 acres inside the outer 3 ft line, so the other half of the water is shallower than 12 feet. The sharpest drop is between 6 and 9 feet, where the mapped water sheds 16 acres.
How accurate is this Riddles Lake depth map?
The contours come from the Indiana DNR Lake Bathymetry survey, retrieved August 2026 and last rebuilt on August 19, 2026. Depths change over time with water levels and sediment, so treat this map as a planning guide for fishing, and never use it for navigation. Per Indiana DNR, the data are graphical representations for reference only, not a survey instrument. Acreages are computed from the published contour geometry, not from a separate area survey, so read them as close approximations.

Depth maps for lakes near Riddles Lake

Mapped fishing venues near Riddles Lake

Riddles Lake in the venue directory covers access and fishing details for this water.

Fishing in Indiana needs a state license: Indiana fishing license guide · all Indiana venues