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Indiana lake depth maps

South Twin Lake depth map

South Twin Lake in LaGrange County, Indiana reaches a depth of 50 feet. South Twin Lake is charted here across 10 closed depth contours, from the 5 ft line down to 50 ft, enclosing about 93 acres of water. Half of that water lies inside the 45 ft line, and only 11 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

South Twin Lake depth chart: 10 depth contours from 5 to 50 ft

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

South Twin Lake depth chart data: water enclosed by each contour
Depth contourWater inside itShare of mapped water
5 ft93 acres100%
10 ft87 acres94%
15 ft84 acres90%
20 ft80 acres86%
25 ft76 acres82%
30 ft70 acres75%
35 ft61 acres66%
40 ft52 acres56%
45 ft40 acres43%
50 ft11 acres12%

Acreages are computed from the closed Indiana DNR Lake Bathymetry contour rings, with islands subtracted. Shares are of the 93 acres inside the outermost charted contour (the 5 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 South Twin Lake: steep sides for its size

The survey encloses about 93 acres of South Twin Lake inside its 5 ft contour, and half of that water lies inside the 45 ft line, so depth comes quickly here, with no long shallow margin before the bottom drops away. Between 45 and 50 ft the mapped water sheds 29 acres in 5 ft of depth, the sharpest change on the chart, start on that band, because it is where the bottom stops being flat. The deepest 50 ft contour holds 11 acres, 12% of the mapped water, toward the northeastern corner of the lake. Nothing here reaches a true cold-water layer at 50 ft, so structure does the thermocline's work: the points and inside turns where the 45 and 50 ft lines pinch together fish hardest in early season, and again as fish follow bait back down in autumn.

Ice fishing on South Twin Lake

At 50 ft, South Twin Lake is a workable ice depth: deep enough to hold fish all winter without the slow freeze-up of a big basin. Start on the 50 ft hole, 11 acres of it, at first light, then move up onto the 45–50 ft break as the sun gets up, and fish the flats inside the 45 ft line through the middle of the day. Check ice thickness locally before you walk out.

South Twin Lake depth map FAQs

How deep is South Twin Lake?
South Twin Lake reaches a maximum depth of 50 feet in the Indiana DNR Lake Bathymetry survey. Most of it is far shallower: the survey charts 10 closed depth contours over about 93 acres, and half of that water sits inside the 45 ft line.
Where is the deepest part of South Twin Lake?
The deepest charted water on South Twin Lake lies inside the 50 ft contour, toward the northeastern corner of the lake. That contour encloses 11 acres, 12% 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 South Twin Lake is shallower than 45 feet?
About half. The 45 ft contour encloses 40 acres of the roughly 93 acres inside the outer 5 ft line, so the other half of the water is shallower than 45 feet. The sharpest drop is between 45 and 50 feet, where the mapped water sheds 29 acres.
How accurate is this South Twin 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 South Twin Lake

Mapped fishing venues near South Twin Lake

South Twin 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