Rock Lake
46.4347° N, 83.7725° W
Depth contours from the 1972 government survey. Not for navigation.
Download the depth map (SVG)Rock Lake, Ontario. 46.4347° N, 83.7725° W
Maximum depth 21.3 m (1972 survey). Scale bar on the map.
Not for navigation. Depths are from government surveys and may be outdated.
borealbound.ca/lakes/on/rock-lake/, 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.
- Fishing access points, 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.
- Lake Partner Program, Ontario Ministry of the Environment, Conservation and Parks. 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.
Rock Lake is 21.3 m deep at its deepest point, deeper than 62% of the 2,688 surveyed lakes in Ontario. It covers 10.7 km² and lies 2.2 km northeast of Plummer.
Government surveys have recorded 16 fish species here, including yellow perch, walleye and rock bass.
- Maximum depth
- 21.3 msurveyed 1972
- deeper than 62% of the 2,688 surveyed lakes in Ontario
- Area
- 10.7 km²
- larger than 95% of the 18,731 lakes in Ontario
- Shoreline
- 23.5 km
- longer than 90% of the 18,731 lakes in Ontario
- Water clarity
- 1.8 mSecchi depth, 2017
- less clear than 90% of the 1,251 monitored lakes in Ontario
- Fish species
- 16
- more than 91% of the 2,454 surveyed lakes in Ontario
- Elevation
- 193 m
Today on the water
10.1 °C
Observed at Sault Ste. Marie, as of 3:00 a.m. EDT
choppy Estimated waves, next 12 hours: up to 0.4 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 30 | NW 30 | NW 30 | NW 30 | NW 15 | var. 5 | E 20 | SE 30 |
| Gusts km/h | 50 | 50 | ||||||
| Waves (est.) m | 0.4 | 0.4 | 0.4 | 0.4 | ||||
| Temp. °C | 8 | 6 | 7 | 11 | 14 | 11 | 7 | 7 |
| Precip. % | 30 | 10 | 10 | 0 | 0 | 0 | 0 | 0 |
Tonight: Mainly cloudy with 60 percent chance of showers. Risk of a thunderstorm after midnight. Wind northwest 30 km/h gusting to 50. Low plus 5.
Weather: Sault Ste. Marie (local forecast), as of 3:06 a.m. EDT
Sun and moon
- Civil dawn
- 7:14 a.m.
- Sunrise
- 7:44 a.m.
- Sunset
- 6:59 p.m.
- Civil dusk
- 7:29 p.m.
- Moonrise
- 6:36 a.m.
- Moonset
- 6:18 p.m.
- Moon
- Waning crescent, 1% lit
Air Quality Health Index
1 low risk
Sault Ste. Marie, as of 2:00 a.m. EDT
Follow this lake by email: a weekly summary of conditions.
Depth
54% of Rock Lake is deeper than 10 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 1972 records a maximum depth of 21.3 m, drawn from 10 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
Sport fish by the share of the 29 government surveys (2011–2011) that recorded them.
Forage fish and other species (8)
Forage fish
- Spottail Shiner 11
- Trout-Perch 7
- Logperch 5
- Bluntnose Minnow 1
- Common Shiner 1
Other
- White Sucker 19
- Brown Bullhead 3
- Shorthead Redhorse 3
Numbers are the surveys that recorded each species.
Eating your catch
The provincial guide to eating fish (2026) sets limits for 3 species from Rock Lake. Maximum meals per month:
| Species | Length | General population | Sensitive population* | Contaminant |
|---|---|---|---|---|
| Northern Pike | 55-60 cm | 4 | Do not eat | Mercury |
| Smallmouth Bass | 35-40 cm | 4 | Do not eat | Mercury |
| Walleye | 40-45 cm | 2 | Do not eat | 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 10. Check seasons and limits before you fish.
Water
Clarity was measured with a Secchi disk in 2 years between 2010 and 2017; the latest annual mean is 1.8 m.
Getting on the water
1 listed boat launch. marks launches on the map.
- Boat launch
Follow this lake
Every Friday by email: the Environment Canada forecast and any weather alerts in effect.