Ontario Lake Depths
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Big Clear Lake

Frontenac County, Ontario · MNRF bathymetric survey
57.9m Mapped depth
190 ft
172 ha 16 contours
Paddling Index66MixedMedium confidencewooded shoreline
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Depth scale

The lake

Survey readout

Big Clear Lake is mapped to a depth of 57.9 m (190 ft) on the Ontario MNRF survey and covers about 172 ha (424 acres) in Frontenac County, Ontario. Depths come from the Ontario MNRF survey of 1969.

Measured from the Ontario MNRF bathymetry survey.

Deepest mapped contour
57.9 m (190 ft)
Survey year
1969
Surface area
172 ha (424 acres)
Shoreline
13.2 km (8.2 mi) · irregular
Fishing access
No MNRF launch listed · check with Frontenac Provincial Park
Borders
Frontenac Provincial Park · Ontario Parks · 54% of shoreline
Additional depth details16 contours
Contour depths
0–57.9 m (190 ft)
Deep-spot markers
57.9 m (190 ft), 45.7 m (150 ft), 39.6 m (130 ft), 33.5 m (110 ft), 27.4 m (90 ft), 21.3 m (70 ft)
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Chart data

Provenance

Sources: Ontario MNRF / LIO Bathymetry, OpenStreetMap (ODbL), Contains information licensed under the Open Government Licence – Ontario, Contains modified Copernicus Sentinel data (Sentinel-2), processed by ontariolakedepths.com, 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 Copernicus Sentinel-2 satellite basemap and OpenStreetMap shoreline. Colour shows surveyed depth; dark lines are the survey's own isobaths.

Coordinates
44.55628, -76.46129
MNRF lake ID
18-3843-49346
Vertical exaggeration
1.4×
Basemap
Copernicus Sentinel-2 · ESA, via Microsoft Planetary Computer
Model size
1.8 MB

Check the source: this lake’s record (18-3843-49346) 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: 1969. This model was built 2026-09-06. Depths between contours are interpolated, not measured.

Paddling

Paddling Index methodology v1.0 · calculated 2026-09-16
66 / 100MixedData confidence: Medium

Big Clear Lake has a heavily wooded and largely undeveloped setting, moderate open-water exposure, some nearby classified roads.

On a canoe route · portages mapped. Portage trails end at this shoreline, including portage. Portages carry canoes over land between waters, and the ground around the lake in the 3D view is terrain those trails cross. Trail condition, length and elevation change are not measured here — check the park or canoe-route map before you go. Trails: OpenStreetMap (ODbL).

Why this score?5 components

Included in the index

ComponentRatingPoints of weightMeasurement
Natural settingExcellent37.9 of 4391% natural land cover within 150 m of shore (83% forest, 3% wetland; 5% developed)
Geometric wind exposureGood19.3 of 36mean fetch 1,251 m · 12% of sampled water within 500 m of shelter · moderate open-water 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 isolationGood9.0 of 21some nearby classified roads · 91 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 — 83% forest and 3% 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.

Angler catch reports

Fish ON-Line · 2021–2022

4 angler trips logged here between August 2021 and May 2022 — too few to show a pattern, so each species is listed with how many trips named it.

Pictures are sized relative to each other. Illustrations are AI-generated representative adults in everyday colours, not photographs (provenance).

Lake Trout3 of 4 trips · 11 caught
Smallmouth Bass1 trip · one angler’s report · 5 caught
Largemouth Bass1 trip · one angler’s report · 1 caught
Trips are logged voluntarily by anglers in Ontario’s Fish ON-Line app. This is what people report catching, not a Ministry survey, and a species nobody has logged may still be here. Contains information licensed under the Open Government Licence – Ontario. Source: Ontario Ministry of Natural Resources, Fish ON-Line. A logged catch does not mean it is legal to catch or keep: check the Ontario Fishing Regulations Summary for this lake’s zone and exceptions.
Quick answers

Big Clear Lake — common questions

How deep is Big Clear Lake?

The deepest contour on the Ontario MNRF bathymetric survey of Big Clear Lake is 57.9 m (190 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 Big Clear Lake?

Big Clear Lake covers about 172 ha (424 acres) in Frontenac County, Ontario.

Is there public access to Big Clear Lake?

No fishing access point for Big Clear Lake appears in the Ontario MNRF fishing access point list (within 100 m of the shoreline), but Big Clear Lake has 54% of its shoreline in Frontenac Provincial Park (Ontario Parks), which runs its own facilities and is not covered by that data. Check with the park for launch details.