How deep is Heart Lake?

Heart Lake reaches a maximum depth of 123 feet in the Michigan DNR Inland Lake Contours survey. Most of it is far shallower: the survey charts 11 closed depth contours over about 64 acres, and half of that water sits inside the 40 ft line. The 123 ft figure is a single recorded sounding rather than a closed contour, so the deepest line you can actually trace on the map is 110 ft.

Where is the deepest part of Heart Lake?

The deepest charted water on Heart Lake lies inside the 110 ft contour, toward the southeastern corner of the lake. That contour encloses under an acre, 1% 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 Heart Lake is shallower than 40 feet?

About half. The 40 ft contour encloses 29 acres of the roughly 64 acres inside the outer 10 ft line, so the other half of the water is shallower than 40 feet. The sharpest drop is between 10 and 20 feet, where the mapped water sheds 16 acres.

How accurate is this Heart Lake depth map?

The contours come from the Michigan DNR Inland Lake Contours 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. Acreages are computed from the published contour geometry, not from a separate area survey, so read them as close approximations.

Michigan lake depth maps

Heart Lake depth map

Heart Lake in Otsego County, Michigan reaches a depth of 123 feet. Heart Lake is charted here across 11 closed depth contours, from the 10 ft line down to 110 ft, enclosing about 64 acres of water. Half of that water lies inside the 40 ft line, and only under an acre lie inside the deepest one. Every contour is on the interactive map below, free and without an account.

Data: Michigan DNR Inland Lake Contours (public record). Contours closed, checked and area-computed by Jordan Carter, founder of GilledIt · page updated August 19, 2026

Heart Lake depth chart: 11 depth contours from 10 to 110 ft

Data: Michigan DNR Inland Lake Contours (public record), retrieved August 2026 · depths change over time · not for navigation

Heart Lake depth chart data: water enclosed by each contour
Depth contour	Water inside it	Share of mapped water
10 ft	64 acres	100%
20 ft	48 acres	74%
30 ft	37 acres	58%
40 ft	29 acres	45%
50 ft	23 acres	35%
60 ft	17 acres	26%
70 ft	12 acres	20%
80 ft	8.2 acres	13%
90 ft	2.8 acres	4.4%
100 ft	1.8 acres	2.9%
110 ft	under 1 acre	1%

Acreages are computed from the closed Michigan DNR Inland Lake Contours contour rings, with islands subtracted. Shares are of the 64 acres inside the outermost charted contour (the 10 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. The survey also records a 123 ft sounding, marked as a point rather than a closed contour, so it is not charted as a band.

Fishing Heart Lake: a stepped drop into deep water

The survey encloses about 64 acres of Heart Lake inside its 10 ft contour, and half of that water lies inside the 40 ft line, so the drop to the deep basin comes in stages, each contour giving up another slice of water, rather than in one abrupt wall. Between 10 and 20 ft the mapped water sheds 16 acres in 10 ft of depth, the sharpest change on the chart, start on that band, because it is where the bottom stops being flat. Inside the 110 ft contour there is under an acre of water, toward the southeastern corner of the lake: a single pocket rather than a basin, and worth a drift over in high summer. 123 ft of water makes this a two-story fishery: warm-water fish hold the 10-to-40 ft ground while the basin can stay cold below the summer thermocline, and the traffic between the two runs along the 10–20 ft break at first and last light.

Ice fishing on Heart Lake

Heart Lake freezes later and less evenly than the shallow waters around it, and the winter bite sets up on the first real break rather than out over the 110 ft hole. The 10–20 ft band on the chart above is that edge: 16 acres of bottom tilt away there, and panfish and walleye slide up and down it through the day. Late ice pushes fish back onto the 10-to-40 ft flat. Check ice thickness locally before you walk out.

Heart Lake depth map FAQs

How deep is Heart Lake?: Heart Lake reaches a maximum depth of 123 feet in the Michigan DNR Inland Lake Contours survey. Most of it is far shallower: the survey charts 11 closed depth contours over about 64 acres, and half of that water sits inside the 40 ft line. The 123 ft figure is a single recorded sounding rather than a closed contour, so the deepest line you can actually trace on the map is 110 ft.
Where is the deepest part of Heart Lake?: The deepest charted water on Heart Lake lies inside the 110 ft contour, toward the southeastern corner of the lake. That contour encloses under an acre, 1% 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 Heart Lake is shallower than 40 feet?: About half. The 40 ft contour encloses 29 acres of the roughly 64 acres inside the outer 10 ft line, so the other half of the water is shallower than 40 feet. The sharpest drop is between 10 and 20 feet, where the mapped water sheds 16 acres.
How accurate is this Heart Lake depth map?: The contours come from the Michigan DNR Inland Lake Contours 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. 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 Heart Lake

Big Bradford Lake depth map · 102 ft max · 2 mi away
Bridge Lake depth map · 87 ft max · 3 mi away
Big Chub Lake depth map · 74+ ft max · 3 mi away
Big Lake depth map · 81 ft max · 10 mi away
Blue Lake depth map · 80+ ft max · 11 mi away

Mapped fishing venues near Heart Lake

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

Big Bradford Lake · 2 mi away
Bridge Lake · 3 mi away
Big Chub Lake · 3 mi away

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