Crow Lake

Where Crow Lake is

Crow Lake lies in the County of Frontenac, with shoreline in the Township of South Frontenac and the Township of Central Frontenac.

How deep is Crow Lake?

The deepest mapped contour on Crow Lake is 33.5 meters, and the water within that boundary descends even farther. Ontario’s bathymetry record holds 45 depth contours for Crow Lake.

See also Ontario's Largest and Deepest Lakes

Surveyed Depths

Ontario has surveyed the depths of several thousand of its lakes over more than half a century. Later surveys were conducted by boat with satellite positioning and produced hundreds of thousands of soundings per lake. Earlier surveys were charted by running transects across the water and drawing depth contours by hand.

Water quality

Ontario’s Lake Partner Program is a volunteer monitoring network. Participants collect water samples for phosphorus analysis and measure water clarity through the summer with a Secchi disk. Most sites are sampled for phosphorus once a year, in spring, and some several times a year between spring and fall. Phosphorus in many lakes rises through the summer, so the two kinds of average are measured on different bases.

Phosphorus is the nutrient that controls how much algae a lake can grow. A lake with little phosphorus stays clear and supports cold-water fish such as lake trout. As phosphorus rises, algae increase, the water clouds, and oxygen in the deep water falls as the algae decay. The province classifies each monitoring site by its average phosphorus:

• Oligotrophic, below 10 micrograms per litre: clear water and low algae.
• Mesotrophic, from 10 to 20: moderately productive water, with more algae and weed growth than an oligotrophic lake but rarely a bloom.
• Eutrophic, above 20: nutrient-rich water, prone to algal blooms and low oxygen at depth.

Crow Lake has 4 Lake Partner monitoring sites. Three have reported phosphorus for the three or more years the province requires before a status is assigned. Two of those sites are classified oligotrophic and one mesotrophic.

The longest record is held by site 6240/1 at Mid Lake, deep spot, with phosphorus sampled once a year over 21 years to 2025. Its long-term mean phosphorus concentration is 8.91 micrograms per litre, within the oligotrophic band, which extends to 10.

A Secchi disk is a white or black-and-white plate lowered on a marked line until it disappears from view. The depth at which it vanishes is the Secchi depth, a direct measure of water clarity. Clearer water gives a deeper reading.

The 210 clarity readings at site 6240/1 give a median Secchi depth of 5.2 meters.

Median Secchi depth by year at site 6240/1

See also Lake Water Quality and Blue-Green Algae in Ontario

Fish in Crow Lake

Ontario’s aquatic resource records name 22 fish species in Crow Lake.

Popular species in the province’s records

• Lake Trouttrout and whitefish
• Lake Whitefishtrout and whitefish
• Ciscotrout and whitefish
• Northern Pikepike
• Walleyeperch
• Yellow Perchperch
• Smallmouth Basssunfish
• Largemouth Basssunfish
• Black Crappiesunfish
• Rock Basssunfish
• Pumpkinseedsunfish
• Bluegillsunfish
• Brown Bullheadcatfish

Spawning areas

Ontario maps 6 fish spawning records within the Crow Lake outline, for three different species, and all of them are mapped below.

By number of records

By area mapped

• Lake Trout4 areas0.7 ha
• Sunfish family1 area0.2 ha
• Walleye1 area0.2 ha

The federal Fisheries Act prohibits the harmful alteration, disruption or destruction of fish habitat without an authorization, so a dock, dredging, infill or shoreline work at a mapped spawning area is reviewed on that basis.

Stocking history

Ontario’s stocking records for Crow Lake run from 1992 to 2007 and hold 13 releases. Lake Trout account for most of the fish: 111,412 released in ten of the years between 1992 and 2007. The last recorded release was 4,000 lake trout yearlings in 2007.

The province’s record of stocking for recreational fishing, kept from 2016, lists no release into Crow Lake.

Eating the fish

The 2026 Guide to Eating Ontario Fish carries consumption advice for seven species taken from Crow Lake, tested for contaminants at a sampling location in Bedford Twp., Frontenac Co. Each figure below is the most meals a month the guide advises for a fish of that length. Where mercury sets the advice, the figure falls as the fish gets longer, because mercury accumulates over a fish’s life. Where the guide has no result yet for certain contaminants at a location, it sets a precautionary limit of 16 meals a month. A zero means the guide advises no meals of that fish at that size.

General population: adultsSensitive population: children under fifteen, women who are or may become pregnant

Fisheries Management Zone 18

Crow Lake lies in Fisheries Management Zone 18. Ontario sets its fishing seasons and catch limits by zone.

Fisheries management zones around Crow Lake

See also Fishing Seasons in Ontario, Zone by Zone and Fish Stocking in Ontario Lakes

Crow Lake Ice Fishing

An ice hut on Crow Lake must be removed by March 15. The province sets dates for ice hut removal as a safety measure to ensure huts are removed before thawing occurs. One date applies to an entire fisheries management zone (FMZ). Crow Lake lies within FMZ 18.

An ice hut must also be removed before the ice breaks up, whether or not that date has passed. The deadline clears huts from the ice ahead of the thaw and does not close the fishing season.

Registration is required in FMZ 18 for an ice hut built of anything other than fabric, and for a fabric tent covering seven square meters or more. Registration is free, and the number is displayed on the outside of the hut.

Ice conditions

No public record reports the thickness or the condition of the ice on Crow Lake on any given day. Ontario publishes ice safety guidance for anyone going out on the ice, at ontario.ca.

See also Lake Ice in Ontario

Islands and names

Crow Lake contains eight islands in the Ontario Hydro Network’s outline, zero of them over 10 hectares and four under a tenth of a hectare.

Nearby lakes

• Bobs Lake5 km away
• Eagle Lake8 km away
• Sharbot Lake9 km away
• Silver Lake14 km away

All lakes

Questions about Crow Lake

• How deep is Crow Lake?

  Its deepest charted contour is 33.5 meters, and the water within it is deeper.

• How big is Crow Lake?

  Its surface covers 4.4 square kilometers and it holds 8 islands. Of its 20 kilometers of shoreline, 18 kilometers is the mainland shore and 2 kilometers is the shore of the islands.

• What fish are in Crow Lake?

  Ontario’s aquatic resource records name 22 species, among them lake trout, walleye, smallmouth bass, largemouth bass, northern pike and lake whitefish.