How deep is Portage Lake?

Portage Lake is more than 40 feet deep. The deepest contour in the Michigan DNR Inland Lake Contours survey is the 40 foot line, and the lake continues deeper inside it, with 10 depth bands mapped in total.

Where is the deepest part of Portage Lake?

The deepest surveyed water on Portage Lake sits toward the eastern side of the lake, inside the 40 ft contour. The interactive depth map above shows the full basin outline and the breaks leading into it.

How accurate is this Portage Lake depth map?

The contours come from the Michigan DNR Inland Lake Contours survey. 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.

Michigan lake depth maps

Portage Lake depth map

Portage Lake in Jackson County, Michigan reaches a depth of more than 40 feet at its deepest surveyed contour. The official Michigan survey maps 10 depth bands across 23 contour lines. This free map of Portage Lake shows every surveyed contour as an interactive depth chart you can use to plan a session before you travel.

Portage Lake depth chart: 10 depth bands to 40+ ft

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

Portage Lake depth chart data
Depth contour	Share of mapped area inside it
1 ft	about 47%
10 ft	about 28%
15 ft	about 22%
20 ft	about 13%
25 ft	about 6%
30 ft	about 4%
35 ft	about 1%
40 ft	under 1%

Share of the surveyed surface area enclosed by each depth contour, computed from the Michigan DNR Inland Lake Contours data.

How to fish Portage Lake: mid-depth structure water

With 40 feet at its deepest, the fish-holding structure is the mid-depth contour: drop-offs, points and inside turns between the shallows and the basin. Use the 10 mapped depth bands to find where contour lines pinch together, which marks the sharpest breaks, and work those edges first, especially early season and again in the fall as fish follow bait between depths.

Ice fishing on Portage Lake

Portage Lake is a classic ice-fishing depth: enough water to hold fish all winter without the long freeze-up of a deep basin. Start on the deepest mapped hole at first light, then work the breaks where contour lines tighten. Mid-depth flats near the basin edge produce through midday. Always verify ice thickness locally before walking out.

Portage Lake depth map FAQs

How deep is Portage Lake?: Portage Lake is more than 40 feet deep. The deepest contour in the Michigan DNR Inland Lake Contours survey is the 40 foot line, and the lake continues deeper inside it, with 10 depth bands mapped in total.
Where is the deepest part of Portage Lake?: The deepest surveyed water on Portage Lake sits toward the eastern side of the lake, inside the 40 ft contour. The interactive depth map above shows the full basin outline and the breaks leading into it.
How accurate is this Portage Lake depth map?: The contours come from the Michigan DNR Inland Lake Contours survey. 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.

Depth maps for lakes near Portage Lake

South Lake depth map · 88 ft max · 10 mi away
Bruin Lake depth map · 48 ft max · 12 mi away
Halfmoon Lake depth map · 87 ft max · 13 mi away
Pickerel Lake depth map · 56 ft max · 14 mi away
Silver Lake depth map · 47+ ft max · 15 mi away

Mapped fishing venues near Portage Lake

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

South Lake · 10 mi away
Bruin Lake · 12 mi away
Halfmoon Lake · 13 mi away

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