Unknown Lake

Thunder Bay District, Ontario · MNRF bathymetric survey

25m Mapped depth
82 ft

75 ha 13 contours Fishing access

Paddling Index87Very Goodaway from major roads · wooded shoreline · sheltered geometry

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Depth scale

0261014182225 m

The lake

Survey readout

Unknown Lake is mapped to a depth of 25 m (82 ft) on the Ontario MNRF survey and covers about 75 ha (185 acres) in Thunder Bay District, Ontario. Depths come from the Ontario MNRF survey of 1987.

Measured from the Ontario MNRF bathymetry survey.

Deepest mapped contour: 25 m (82 ft)
Survey year: 1987
Surface area: 75 ha (185 acres)
Shoreline: 3.5 km (2.1 mi) · round
Fishing access: 1 MNRF fishing access point · 1 boat launch

Additional depth details13 contours

Contour depths: 0–25 m (82 ft)
Deep-spot markers: 25 m (82 ft), 18 m (59 ft), 14 m (46 ft)

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Location

Thunder Bay District, Ontario · 15 nearest of 285 lakes and 3 rivers · tap a dot to open it

Chart data

Provenance

Sources: Ontario MNRF / LIO Bathymetry, Ontario FRI Leaf-On Imagery, Ontario FRI LiDAR DTM, OpenStreetMap (ODbL), Contains information licensed under the Open Government Licence – Ontario.

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Map details & sources5 sources

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

Survey-derived depth contours drape over Ontario LiDAR (FRI DTM) elevation, with a Ontario FRI aerial basemap and OpenStreetMap shoreline. Colour shows surveyed depth; dark lines are the survey's own isobaths.

Coordinates: 48.97981, -88.72082
MNRF lake ID: 16-3744-54268
Vertical exaggeration: 1.4×
Basemap: Ontario FRI
Model size: 1.2 MB

Check the source: this lake’s record (16-3744-54268) in the Ontario MNRF bathymetry index, and the contour line layer the map is drawn from (Land Information Ontario open data, Open Government Licence – Ontario). Survey year: 1987. This model was built 2026-09-07. Depths between contours are interpolated, not measured.

Paddling

Paddling Index methodology v1.0 · calculated 2026-09-16

87 / 100Very GoodData confidence: High

Unknown Lake has a heavily wooded and largely undeveloped setting, generally sheltered geometry, little nearby major-road exposure.

Why this score?5 components

Included in the index

Component	Rating	Points of weight	Measurement
Natural setting	Excellent	34.7 of 35	98% natural land cover within 150 m of shore (97% forest, 0% wetland; 0% developed)
Geometric wind exposure	Very Good	19.4 of 29	mean fetch 912 m · 0% of sampled water within 500 m of shelter · generally short fetch
Motor & speed rules	Not modelled	—	Canada publishes vessel motor and speed restrictions as federal legal schedules, not map data, so they are not part of the Ontario index. Check local signage and Transport Canada rules before going out.
Public access	Good	15.0 of 18	1 MNRF fishing access point · boat ramp
Road isolation	Excellent	17.6 of 18	relatively isolated from major roads · 1 Ontario Road Network segment within 1.2 km (traffic estimated from road class, not measured)

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
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 — 97% forest and 0% wetland cover within 150 m of shore
Mapped wildlife habitat: None mapped — Ontario MNRF has not mapped moose, deer or waterfowl habitat within 1 km of this lake. The province maps these areas where it has surveyed, so this is not evidence that wildlife is absent. · Ontario MNRF Wildlife Values Area. Contains information licensed under the Open Government Licence – Ontario.

Compare Ontario 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 road-network 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 Ontario lakes: natural setting 35%, geometric wind exposure 29%, public access 18%, road isolation 18%. Motor and speed restrictions are not modelled for Ontario, and road traffic is estimated from road class, not measured. Where a component has no data the remaining weights are renormalized and the confidence rating is lowered; below Medium confidence no number is shown. Ontario scores are relative to other Ontario lakes and are not directly comparable with Paddling Index scores on our sister sites, which use different data sources and include a watercraft-rules component. Sources: Ontario MNRF bathymetry outline (0 m contour or survey index polygon), Ontario Land Cover v1.0, Ontario MNRF (Open Government Licence – Ontario) (2020), Ontario MNRF Fishing Access Points (Open Government Licence – Ontario) (2026-09) and Ontario Road Network (Open Government Licence – Ontario); traffic estimated by road class, not measured (2026-09). Conditions change quickly — check current weather and local conditions before going out.

Quick answers

Unknown Lake — common questions

How deep is Unknown Lake?

The deepest contour on the Ontario MNRF bathymetric survey of Unknown Lake is 25 m (82 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 Unknown Lake?

Unknown Lake covers about 75 ha (185 acres) in Thunder Bay District, Ontario.

Is there public access to Unknown Lake?

The Ontario MNRF lists 1 fishing access point within 100 m of the shoreline of Unknown Lake: 1 boat launch. The list includes municipal and privately owned sites, and some may charge a fee or restrict parking, so it confirms a place anglers use rather than a public right of way. Check locally before you go.

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