How deep is Halfmoon Lake?

Halfmoon Lake reaches a maximum depth of 87 feet in the Michigan DNR Inland Lake Contours survey. Most of it is far shallower: the survey charts 8 closed depth contours over about 148 acres, and half of that water sits inside the 40 ft line. The 87 ft figure is a single recorded sounding rather than a closed contour, so the deepest line you can actually trace on the map is 80 ft.

Where is the deepest part of Halfmoon Lake?

The deepest charted water on Halfmoon Lake lies inside the 80 ft contour, toward the middle of the lake. That contour encloses 3.5 acres, 2.4% 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 Halfmoon Lake is shallower than 40 feet?

About half. The 40 ft contour encloses 67 acres of the roughly 148 acres inside the outer 10 ft line, so the other half of the water is shallower than 40 feet. The sharpest drop is between 30 and 40 feet, where the mapped water sheds 32 acres.

How accurate is this Halfmoon 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

Halfmoon Lake depth map

Halfmoon Lake in Washtenaw County, Michigan reaches a depth of 87 feet. Halfmoon Lake is charted here across 8 closed depth contours, from the 10 ft line down to 80 ft, enclosing about 148 acres of water. Half of that water lies inside the 40 ft line, and only 3.5 acres 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

Halfmoon Lake depth chart: 8 depth contours from 10 to 80 ft

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

Halfmoon Lake depth chart data: water enclosed by each contour
Depth contour	Water inside it	Share of mapped water
10 ft	148 acres	100%
20 ft	130 acres	88%
30 ft	99 acres	67%
40 ft	67 acres	45%
50 ft	45 acres	31%
60 ft	29 acres	19%
70 ft	9.6 acres	6.5%
80 ft	3.5 acres	2.4%

Acreages are computed from the closed Michigan DNR Inland Lake Contours contour rings, with islands subtracted. Shares are of the 148 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 87 ft sounding, marked as a point rather than a closed contour, so it is not charted as a band.

Fishing Halfmoon Lake: a stepped drop into deep water

The survey encloses about 148 acres of Halfmoon 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 30 and 40 ft the mapped water sheds 32 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. The deepest 80 ft contour holds 3.5 acres, 2.4% of the mapped water, toward the middle of the lake. 87 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 30–40 ft break at first and last light.

Ice fishing on Halfmoon Lake

Halfmoon 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 80 ft hole. The 30–40 ft band on the chart above is that edge: 32 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.

Halfmoon Lake depth map FAQs

How deep is Halfmoon Lake?: Halfmoon Lake reaches a maximum depth of 87 feet in the Michigan DNR Inland Lake Contours survey. Most of it is far shallower: the survey charts 8 closed depth contours over about 148 acres, and half of that water sits inside the 40 ft line. The 87 ft figure is a single recorded sounding rather than a closed contour, so the deepest line you can actually trace on the map is 80 ft.
Where is the deepest part of Halfmoon Lake?: The deepest charted water on Halfmoon Lake lies inside the 80 ft contour, toward the middle of the lake. That contour encloses 3.5 acres, 2.4% 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 Halfmoon Lake is shallower than 40 feet?: About half. The 40 ft contour encloses 67 acres of the roughly 148 acres inside the outer 10 ft line, so the other half of the water is shallower than 40 feet. The sharpest drop is between 30 and 40 feet, where the mapped water sheds 32 acres.
How accurate is this Halfmoon 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 Halfmoon Lake

Bruin Lake depth map · 48 ft max · 1 mi away
Pickerel Lake depth map · 56 ft max · 2 mi away
Silver Lake depth map · 47+ ft max · 3 mi away
South Lake depth map · 88 ft max · 3 mi away
Bass Lake depth map · 73 ft max · 8 mi away

Mapped fishing venues near Halfmoon Lake

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

Bruin Lake · 1 mi away
Pickerel Lake · 2 mi away
Silver Lake · 3 mi away

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