Michigan lake depth maps

Long Lake depth map

Long Lake in Iron County, Michigan reaches a depth of 105 feet. The official Michigan survey maps 15 depth bands across 17 contour lines. This free map of Long Lake shows every surveyed contour as an interactive depth chart you can use to plan a session before you travel.

Long Lake depth chart: 15 depth bands to 105 ft

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

Long Lake depth chart data
Depth contourShare of mapped area inside it
5 ftabout 100%
10 ftabout 86%
15 ftabout 76%
20 ftabout 70%
25 ftabout 64%
30 ftabout 55%
35 ftabout 47%
40 ftabout 39%
50 ftabout 33%
60 ftabout 26%
70 ftabout 19%
80 ftabout 12%
90 ftabout 8%
100 ftabout 6%

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

How to fish Long Lake: deep, two-story water

At 105 feet, this is a two-story fishery: warm-water species work the shallows and weed edges while the deep basin can hold cold-water fish below the summer thermocline. In summer, target the transition where the bottom breaks from the shallow shelf toward the basin; fish suspend along that edge at dawn and dusk. The 15 mapped depth bands make it straightforward to find those breaks before you launch.

Ice fishing on Long Lake

On deep water like Long Lake, the winter bite concentrates along the first major drop-off rather than the deepest basin. Use the contours above to find where the shallow shelf breaks toward deep water and set up on that edge; panfish and walleye slide up and down it through the day. Late ice often pushes fish shallower again. Always verify ice thickness locally before walking out, and remember deep lakes freeze later and less evenly than shallow ones.

Long Lake depth map FAQs

How deep is Long Lake?
Long Lake reaches a maximum depth of 105 feet, according to the Michigan DNR Inland Lake Contours survey. Most of the lake is shallower, with 15 mapped depth bands between the shoreline and the deepest hole.
Where is the deepest part of Long Lake?
The deepest surveyed water on Long Lake sits toward the middle of the lake, inside the 105 ft contour. The interactive depth map above shows the full basin outline and the breaks leading into it.
How accurate is this Long 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 Long Lake

Mapped fishing venues near Long Lake

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

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