Ontario Lake Depths
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Gargantua Lake

Algoma District, Ontario · MNRF bathymetric survey
26m Mapped depth
85 ft
53 ha 15 contours
Paddling Index92ExcellentMedium confidenceaway from major roads · wooded shoreline · sheltered geometry
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Depth scale

The lake

Survey readout

Gargantua Lake is mapped to a depth of 26 m (85 ft) on the Ontario MNRF survey and covers about 53 ha (130 acres) in Algoma District, Ontario. Depths come from the Ontario MNRF survey of 1978.

Measured from the Ontario MNRF bathymetry survey.

Deepest mapped contour
26 m (85 ft)
Survey year
1978
Surface area
53 ha (130 acres)
Shoreline
6.2 km (3.9 mi) · irregular
Fishing access
No MNRF launch listed · check with Lake Superior Provincial Park
In
Lake Superior Provincial Park · Ontario Parks
Additional depth details15 contours
Contour depths
0–26 m (85 ft)
Deep-spot markers
26 m (85 ft)
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Chart data

Provenance

Sources: Ontario MNRF / LIO Bathymetry, Ontario FRI Leaf-On Imagery, OpenStreetMap (ODbL), Contains information licensed under the Open Government Licence – Ontario, Copernicus DEM 30 m (© DLR/Airbus).

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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 Copernicus DEM (30 m) elevation, with a Ontario FRI aerial basemap and OpenStreetMap shoreline. Colour shows surveyed depth; dark lines are the survey's own isobaths.

Coordinates
47.62784, -84.89464
MNRF lake ID
16-6582-52769
Vertical exaggeration
1.4×
Basemap
Ontario FRI
Model size
2.1 MB

Check the source: this lake’s record (16-6582-52769) 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: 1978. This model was built 2026-09-08. Depths between contours are interpolated, not measured.

Paddling

Paddling Index methodology v1.0 · calculated 2026-09-16
92 / 100ExcellentData confidence: Medium

Gargantua 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

ComponentRatingPoints of weightMeasurement
Natural settingExcellent40.5 of 4394% natural land cover within 150 m of shore (92% forest, 2% wetland; 0% developed)
Geometric wind exposureVery Good29.8 of 36mean fetch 634 m · 23% of sampled water within 500 m of shelter · generally short fetch
Motor & speed rulesNot 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 accessNot listed—No publicly listed MNRF fishing access point within 100 m of this shoreline. Municipal, private and informal launches are not all in this source, so this is not evidence that access is poor — the component is excluded and the remaining weights are renormalized.
Road isolationExcellent21.4 of 21relatively isolated from major roads · 0 Ontario Road Network segments 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 — 92% forest and 2% 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.
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) 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

Gargantua Lake — common questions

How deep is Gargantua Lake?

The deepest contour on the Ontario MNRF bathymetric survey of Gargantua Lake is 26 m (85 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 Gargantua Lake?

Gargantua Lake covers about 53 ha (130 acres) in Algoma District, Ontario.

Is there public access to Gargantua Lake?

No fishing access point for Gargantua Lake appears in the Ontario MNRF fishing access point list (within 100 m of the shoreline), but Gargantua Lake lies inside Lake Superior Provincial Park (Ontario Parks), which runs its own facilities and is not covered by that data. Check with the park for launch details.