Portage Lake

Cass County, Minnesota · MN DNR bathymetric survey

80ft Max
depth

283 acres 8 contours

Paddling Index63MixedMedium confidencewooded shoreline

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Depth scale

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The lake

Survey readout

Portage Lake is mapped to a depth of 80 ft on the Minnesota DNR survey and covers about 283 acres in Cass County, Minnesota.

Measured from the Minnesota DNR lake bathymetric contour survey.

Deepest mapped contour: 80 ft
Surface area: 283 acres
Shoreline: 3.08 mi · lobed
Aquatic vegetation: 2% of surface · NDVI estimate
Public access: No public DNR launch identified

Additional depth details8 contours

Contour depths: 0–80 ft
Recorded point soundings: 80 ft, 60 ft, 60 ft, 40 ft

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Location

Cass County, Minnesota · 15 nearest of 123 lakes · tap a dot for that lake

Chart data

Provenance

Sources: MN DNR Lake Bathymetric Contours, USGS 3DEP, USDA NAIP (public domain), OpenStreetMap (ODbL).

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Map details & sources4 sources

All layers registered to one bounding box; positions in WGS 84.

Survey-derived depth contours drape over USGS 3DEP elevation, with a USDA NAIP aerial basemap and OpenStreetMap shoreline. Color shows surveyed depth; dark lines are the survey's own isobaths.

Coordinates: 47.01011, -94.55313
MN DNR lake ID: 11047600
Vertical exaggeration: 1.4×
Basemap: USDA NAIP · public domain
Model size: 2.3 MB

Paddling

Paddling Index methodology v1.0 · calculated 2026-09-25

63 / 100MixedData confidence: Medium

Portage Lake has a mostly natural, lightly developed setting, moderate open-water exposure, some nearby classified roads.

Why this score?5 components

Included in the index

Component	Rating	Points of weight	Measurement
Natural setting	Very Good	31.4 of 43	76% natural land cover within 150 m of shore (47% forest, 24% wetland; 15% developed)
Geometric wind exposure	Good	18.6 of 36	mean fetch 1,279 m · 0% of sampled water within 500 m of shelter · moderate open-water fetch
Motor & speed rules	Not modeled	—	Minnesota’s lake-by-lake motor, speed and no-wake rules are mostly county and city ordinances, not map data, so they are not part of the Minnesota index. Check local signage and ordinances before going out.
Public access	Not listed	—	No public access site of this lake’s own in the MN DNR water access and fishing site records. Private, commercial and informal launches are not all in these records, so this is not evidence that access is poor — the component is excluded and the remaining weights are renormalized.
Road isolation	Good	12.7 of 21	some nearby classified roads · 4 MnDOT-classified segments within 1.2 km, peak 4,279 vehicles/day

Additional paddling considerations

These describe the lake but are not part of the v1 Paddling Index and do not change the number above.

Wake sensitivity: Low — wide enough that wakes disperse over most of the lake
Aquatic vegetation: Low — approximately 2% mapped coverage · NAIP aerial imagery (NDVI)
Observed motorized activity: Unknown — No lake-level measurement of boat traffic is available. Legal permission to operate motors is not evidence of use.
Wildlife habitat potential: High — 47% forest and 24% wetland cover within 150 m of shore

Compare Minnesota lakes by Paddling Index →

How this index is calculated. The Paddling Index is a relative composite derived from lake geometry and public land-cover, access and traffic-count data. It is not a user review, a safety rating, or a prediction of an individual outing. Differences of a few points should not be treated as meaningful — an 84 and an 82 are broadly comparable. Components and weights for Minnesota lakes: natural setting 35%, geometric wind exposure 29%, public access 18%, road isolation 18%. Motor, speed and no-wake rules are not modeled for Minnesota, and traffic counts cover state, county and some city roads but not township roads. Where a component has no data the remaining weights are renormalized and the confidence rating is lowered; below Medium confidence no number is shown. Minnesota scores are relative to other Minnesota lakes and are not directly comparable with Paddling Index scores on our sister sites, which use different data sources, some with a watercraft-rules component. Sources: MN DNR lake bathymetry outline, USGS/MRLC NLCD Land Cover (2021) and MnDOT Annual Average Daily Traffic (counts 2019–2025). Conditions change quickly — check current weather and local conditions before going out.

Fish you might catch

from DNR surveys & active stocking

10 species with recent evidence in this lake — sized relative to each other. Illustrations are AI-generated representative adults in everyday colors, not photographs (provenance).

White Sucker

Hybrid Sunfish

About these fish → the Fish of Minnesota guide

Compiled from Minnesota DNR fishery surveys and Minnesota DNR stockings within the last 10 years. Silhouettes are stylized and scaled to typical adult sizes relative to one another. Presence is not a promise — fishing isn’t a sure thing.

Fishery

surveyed 2025

312Fish sampled

10Species

Gamefish Northern Pike 32 · Largemouth Bass 14 · Walleye 12 · Smallmouth Bass 7

Panfish Bluegill 137 · Yellow Perch 45 · Pumpkinseed 26

All survey species10 species

Gamefish

Northern Pike32 caught · to 39″

Largemouth Bass14 caught · to 11″

Walleye12 caught · to 22″

Smallmouth Bass7 caught · to 16″

Panfish

Bluegill137 caught · to 8″

Yellow Perch45 caught · to 9″

Pumpkinseed26 caught · to 7″

Hybrid Sunfish8 caught · to 8″

Black Crappie7 caught · to 12″

Forage & nongame

White Sucker24 caught · to 24″

Length is the largest fish netted in the survey, not an angler record. Source: Minnesota DNR lake survey (LakeFinder).

DNR stocking

state stocking record · 2017–2025

Fish the Minnesota DNR has planted in this lake — what was added, distinct from what a survey netted above.

Walleye389,250 stocked · 2017–2025 · 8 plantings

Source: Minnesota DNR LakeFinder stocking report. LakeFinder lists the last 10 years of stocking only.

Infested waters listing

1 confirmed

Plants & algae

Eurasian WatermilfoilConfirmed in this water in 2026 (listed 2026).

How to identify invasive species in Minnesota lakes →

What does the infested waters list mean?

The Minnesota DNR lists a lake, river, pond or wetland as infested when it contains an aquatic invasive species that could spread to other waters, or when it is connected to a water where one is present. Activities such as bait harvest and water use are managed differently on infested waters. Check the current list before moving water, bait or equipment.

Source: Minnesota Department of Natural Resources. List of Infested Waters, September 9, 2026. https://www.dnr.state.mn.us/invasives/ais/infested.html

Quick answers

Portage Lake — common questions

How deep is Portage Lake?

The deepest contour on the Minnesota DNR bathymetric survey of Portage Lake is 80 ft. That is the deepest depth the historical survey map records, which may differ from the deepest point of the lake itself.

How big is Portage Lake?

Portage Lake covers about 283 acres in Cass County, Minnesota.

What fish are in Portage Lake?

Species with survey, catch or recent-stocking evidence include largemouth bass, northern pike, smallmouth bass, walleye, black crappie, bluegill. The page lists all 10 species and the evidence behind each.

Is there public access to Portage Lake?

No public launch for Portage Lake appears in the Minnesota DNR access data. That is not the same as the lake being private -- private and commercial launches are not in that source.