Long Lake
46.2969° N, 78.8557° W
Depth contours from the 2023 government survey. Not for navigation.
Download the depth map (SVG)Long Lake, Ontario. 46.2969° N, 78.8557° W
Maximum depth 49 m (2023 survey). Scale bar on the map.
Not for navigation. Depths are from government surveys and may be outdated.
borealbound.ca/lakes/on/long-lake-near-mattawa/, compiled October 9, 2026
- Canadian Geographical Names Database, Natural Resources Canada. Contains information licensed under the Open Government Licence – Canada.
- HydroLAKES v1.0, Messager et al. 2016 / WWF HydroSHEDS. Licensed under CC BY 4.0.
- Census boundaries and population, 2021, Statistics Canada. Adapted from Statistics Canada. This does not constitute an endorsement by Statistics Canada.
- Aquatic Resource Area survey points, Ontario Ministry of Natural Resources. Contains information licensed under the Open Government Licence – Ontario.
- Fish stocking for recreational purposes, Ontario Ministry of Natural Resources. Contains information licensed under the Open Government Licence – Ontario.
- Fisheries Management Zones, Ontario Ministry of Natural Resources. Contains information licensed under the Open Government Licence – Ontario.
- Bathymetry lines and survey index, Ontario Ministry of Natural Resources. Contains information licensed under the Open Government Licence – Ontario.
- City page weather forecasts and alerts, Environment and Climate Change Canada. Contains data from Environment and Climate Change Canada (ECCC Data Servers End-use Licence).
- Air Quality Health Index observations and forecasts, Environment and Climate Change Canada. Contains data from Environment and Climate Change Canada (ECCC Data Servers End-use Licence).
- Guide to Eating Ontario Fish: Advisory Database, Ontario Ministry of the Environment, Conservation and Parks. Contains information licensed under the Open Government Licence – Ontario.
Long Lake is 49 m deep at its deepest point, deeper than 94% of the 2,688 surveyed lakes in Ontario. It covers 0.19 km² and lies 5.7 km north of Eau Claire.
Government surveys have recorded 2 fish species here: brook trout and splake.
- Maximum depth
- 49 msurveyed 2023
- deeper than 94% of the 2,688 surveyed lakes in Ontario
- Area
- 0.19 km²
- smaller than 81% of the 18,731 lakes in Ontario
- Shoreline
- 4.3 km
- shorter than 58% of the 18,731 lakes in Ontario
- Fish species
- 2
- fewer than 60% of the 2,454 surveyed lakes in Ontario
- Elevation
- 173 m
Today on the water
4.1 °C
Observed at North Bay, as of 3:00 a.m. EDT
calm Estimated waves, next 12 hours: up to 0.1 m. Around 4 a.m., wind from the west: the west shore is sheltered, waves build toward the east shore.
| Time | 4 a.m. | 7 a.m. | 10 a.m. | 1 p.m. | 4 p.m. | 7 p.m. | 10 p.m. | 1 a.m. |
|---|---|---|---|---|---|---|---|---|
| Wind km/h | W 10 | W 10 | NW 20 | W 20 | NW 20 | N 10 | NE 10 | E 10 |
| Gusts km/h | 40 | |||||||
| Waves (est.) m | 0.1 | 0.1 | 0.1 | 0.1 | ||||
| Temp. °C | 5 | 4 | 7 | 11 | 14 | 11 | 6 | 4 |
| Precip. % | 30 | 30 | 30 | 20 | 20 | 0 | 0 | 0 |
Tonight: Mainly cloudy with 30 percent chance of showers. Wind west 20 km/h gusting to 40 becoming light early this evening. Low plus 4.
Weather: North Bay (local forecast), as of 3:01 a.m. EDT
Sun and moon
- Civil dawn
- 6:54 a.m.
- Sunrise
- 7:24 a.m.
- Sunset
- 6:39 p.m.
- Civil dusk
- 7:09 p.m.
- Moonrise
- 6:16 a.m.
- Moonset
- 5:58 p.m.
- Moon
- Waning crescent, 1% lit
Air Quality Health Index
1 low risk
North Bay, as of 2:00 a.m. EDT
Follow this lake by email: a weekly summary of conditions.
Depth
35% of Long Lake is deeper than 20 m.
How to read it: the lake’s area is sorted from the shore to the deepest point. Where the curve is flat, large areas share one depth (flats and weed beds); where it drops, depth changes quickly (drop-offs).
The government depth survey from 2023 records a maximum depth of 49 m, drawn from 305 depth contours.
- Download the depth map (SVG)Printing this page gives the map on one sheet, with scale and sources.
Not for navigation. Depths are from government surveys and may be outdated.
Fish
- Brook TroutStocked
- SplakeStocked
Stocking
Splake5,000 fish in 2 years, most recently 2018
Brook Trout2,375 fish in 3 years, most recently 2025
All stocking records (5)
| Year | Species | Fish | Stage |
|---|---|---|---|
| 2025 | Brook Trout | 500 | Yearlings |
| 2024 | Brook Trout | 1,200 | Yearlings |
| 2022 | Brook Trout | 675 | Yearlings |
| 2018 | Splake | 2,500 | Yearlings |
| 2016 | Splake | 2,500 | Yearlings |
Eating your catch
The provincial guide to eating fish (2026) sets limits for 1 species from Long Lake. Maximum meals per month:
| Species | Length | General population | Sensitive population* | Contaminant |
|---|---|---|---|---|
| Splake | 45-50 cm | 12 | 4 | Mercury |
* As defined in the guide, including children and people who are or may become pregnant. Limits are for the length the guide lists most often; they change with the size of the fish. Read the official guide
Fishing regulations: Fisheries Management Zone 11. Check seasons and limits before you fish.
Follow this lake
Every Friday by email: the Environment Canada forecast and any weather alerts in effect.