Thunder Bay District, Ontario

Dog Lake

One hundred and forty-six square kilometers north of Thunder Bay, with 121 islands and a deepest charted contour of 100.0 meters. Cool water, and the aquatic resource record lists fifteen species.

Surface: 145.9 km²
Shoreline: 373 km294 mainland + 79 islands
Islands: 121
Charted depth: 100.0 m
Depth contours: 339

All figures are derived from Ontario’s survey records.

Where Dog Lake is

Dog Lake lies in the District of Thunder Bay.

How deep is Dog Lake?

The deepest mapped contour on Dog Lake is 100.0 meters, and the water within that boundary descends even farther. Ontario’s bathymetry record holds 339 depth contours for Dog Lake.

The deepest charted contour on Dog Lake, 100.0 meters. The circle marks the centre of that contour, and the water within it is deeper. Of the survey’s 339 contours, 130 are its own shoreline contour, one ring around the mainland and one around each island it charted, and are left off, the outline being the Ontario Hydro Network’s; the other 209 depth contours are drawn where the province published them, and along the outline where the survey placed them beyond it. Outline from the Ontario Hydro Network. Each contour is labelled with its depth in meters; zoom in where they run close.

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 a water sample each spring for phosphorus analysis and measure water clarity through the summer with a Secchi disk.

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 spring phosphorus. Below 10 micrograms per litre is oligotrophic: clear water and low algae. From 10 to 20 is mesotrophic: moderately productive water, with more algae and weed growth than an oligotrophic lake but rarely a bloom. Above 20 is eutrophic: nutrient-rich water, prone to algal blooms and low oxygen at depth.

A Secchi disk is a 20 centimeter 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.

No monitoring site on Dog Lake is registered with the Lake Partner Program, so no phosphorus or clarity record exists for the lake.

Fish in Dog Lake

Ontario’s aquatic resource records name 14 fish species in Dog Lake. The province classes the lake as cool water. The record took effect on 7 November 2018, and it compiles what field biologists had reported by then. The province’s other records for the lake name two further species, lake trout and splake. They appear in the records below.

Seven of the sixteen species in the province’s records

Lake Whitefishtrout and whitefish
Ciscotrout and whitefish
Northern Pikepike
Walleyeperch
Yellow Perchperch
Smallmouth Basssunfish
Burbotcod

The other nine species in the province’s records, with one observation the province could not identify
Family	Species
Trout and whitefish	lake trout, splake
Sucker	longnose sucker, white sucker
Minnow	spottail shiner
Sculpin	deepwater sculpin
Trout-perch	trout-perch
Other	smelts, trout-perches

Stocking history

Ontario’s stocking records for Dog Lake run from 1999 to 2004 and hold 30 releases. Splake account for most of the fish: 246,293 released in six of the years between 1999 and 2004. The last recorded release was 24,313 splake yearlings in 2004.

Fish released into Dog Lake, 1999 to 2004
Species	Years	Years with a release	Fish released
Splake	1999 to 2004	6	246,293
Lake Trout	1999 to 2003	5	200,822

The province’s current stocking programme, recorded from 2016, lists no release into Dog Lake.

Eating the fish

The 2025 Guide to Eating Ontario Fish carries consumption advice for seven species taken from Dog Lake, tested for contaminants at a sampling location in northwest of Thunder Bay, Thunder Bay Dist. Each figure below is the most meals a month the guide advises for a fish of that length. The advice falls as the fish gets longer, because mercury accumulates over a fish’s life. 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

Lake Whitefish Mercury
Length, cm	40 to 45	45 to 50	50 to 55
General population	16	16	12
Sensitive population	8	4	4

Walleye Mercury
Length, cm	25 to 30	30 to 35	35 to 40	40 to 45	45 to 50	50 to 55	55 to 60	60 to 65	65 to 70	70 to 75
General population	12	8	4	4	2	2	0	0	0	0
Sensitive population	4	4	0	0	0	0	0	0	0	0

Northern Pike Mercury
Length, cm	20 to 25	25 to 30	30 to 35	35 to 40	40 to 45	45 to 50	50 to 55	55 to 60	60 to 65	65 to 70	70 to 75	over 75
General population	16	16	16	12	8	8	8	4	4	4	4	2
Sensitive population	8	8	4	4	4	4	0	0	0	0	0	0

Smallmouth Bass Mercury
Length, cm	25 to 30	30 to 35	35 to 40	40 to 45	45 to 50
General population	8	8	4	4	2
Sensitive population	4	4	0	0	0

Burbot Mercury
Length, cm	40 to 45	45 to 50	50 to 55
General population	8	4	4
Sensitive population	0	0	0

White Sucker Mercury
Length, cm	45 to 50	50 to 55	55 to 60
General population	16	8	8
Sensitive population	4	4	0

Longnose Sucker Mercury
Length, cm	45 to 50	50 to 55	55 to 60
General population	8	4	4
Sensitive population	4	0	0

Fisheries Management Zone 6

Dog Lake lies in Fisheries Management Zone 6. Ontario sets its fishing seasons and catch limits by zone.

Zone 6 seasons and limits, 2026
Species	Open season	Sport licence	Conservation licence
Atlantic Salmon	Open all year	1	0
Brook Trout	4th Sat. in Apr. – Labour Day	5, not more than 1 greater than 30 cm (11.8 in.)	2, not more than 1 greater than 30 cm (11.8 in.)
Brown Trout	Open all year	5	2
Channel Catfish	Open all year	12	6
Crappie	Open all year	15	10
Lake Trout	Jan. 1 – Sept. 30	2, not more than 1 greater than 56 cm (22 in.) from Sept. 1 – Sept. 30; no size limit rest of year	1, no size limit
Lake Whitefish	Open all year	12	6
Largemouth and Smallmouth Bass or any combination	Open all year	4	2
Muskellunge	3rd Sat. in June – Dec. 15	1, must be greater than 91 cm (36 in.)	0
Northern Pike	Open all year	4, not more than 1 greater than or equal to 70 cm (27.6 in.)	2, not more than 1 greater than or equal to 70 cm (27.6 in.)
Pacific Salmon	Open all year	5	2
Rainbow Trout	Open all year	1	0
Splake	Open all year	5	2
Sunfish	Open all year	50	25
Walleye and Sauger or any combination	Jan. 1 – Apr. 14 & 3rd Sat. in May – Dec. 31	4, not more than 1 greater than 46 cm (18.1 in.)	2, not more than 1 greater than 46 cm (18.1 in.)
Yellow Perch	Open all year	50	25

The figures are the number of fish an angler may catch and keep in a day and have in possession, under a sport fishing licence and under a conservation licence. The rows are the whole zone’s, and they apply to every lake in it. No waterbody exception names Dog Lake. Zone-wide, Smelt may not be used as bait or possessed for use as bait except where exceptions apply.

Islands and names

Dog Lake contains 121 islands in the Ontario Hydro Network’s outline, twelve of them over 10 hectares and 36 under a tenth of a hectare. One of them lies inside a wetland mapped in the province’s Wetland With Significance dataset.

The ten largest islands outside a mapped wetland, numbered to the table. Areas are measured on the province’s outline.

The ten largest islands outside a mapped wetland
	Island	Hectares
1	unnamed	119.9
2	Big Island	57.2
3	unnamed	54.9
4	unnamed	52.9
5	unnamed	43.1
6	unnamed	34.3
7	unnamed	34.0
8	unnamed	16.5
9	unnamed	14.8
10	unnamed	14.1

Official names

Ontario’s geographic names register lists 10 official names on the water and its islands: 1 island and seven bays. A further 1 named point stands on the mainland shore.

Bays 7

Buda Bay
Creighton Bay
East Bay
Hawk Bay
North Bay
Stirrett Bay
Walberg Bay

Points on the shore 1

Bad Point

Nearby lakes

All lakes

Questions about Dog Lake

How deep is Dog Lake?
Its deepest charted contour is 100 meters, and the water within it is deeper.
How big is Dog Lake?
Its surface covers 145.9 square kilometers and it holds 121 islands. Of its 373 kilometers of shoreline, 294 kilometers is the mainland shore and 79 kilometers is the shore of the islands.
What fish are in Dog Lake?
Ontario’s aquatic resource records name fourteen species, among them walleye, smallmouth bass, northern pike, lake whitefish and yellow perch. The lake’s spawning, consumption and stocking records also name lake trout and splake.

A print of Dog Lake

Dog Lake has not yet been drawn as a print. The lakes drawn so far are on the lake maps page, and a print of Dog Lake can be requested by email; whether it can be drawn is confirmed before any payment.

Ask about a Dog Lake print

Looking at a property on Dog Lake?

Depth and water quality are two records out of many. Our Rural & Cottage Buyer’s Report gathers what the public record holds about one specific address: shore road allowance, road access, wells, flood mapping, Crown land, wetlands and more, read and checked by a person before it is sent.

See what is in the report

What these figures do and do not say

Depth: A depth reading is the distance from the water surface on the day of survey to the lake bottom. Lake levels vary through the season and between years. The depth figure above is the deepest contour charted and is a minimum; the depth within it was not recorded. The figures for Dog Lake are read from the province’s bathymetry records within the Ontario Hydro Network’s outline of the lake: the deepest figure is the deepest record inside that outline, and the count is every record inside it.
Shoreline and surface: The shoreline figure is the length of the mainland shore and of every island shore added together, measured on the Ontario Hydro Network’s outline of the lake. The surface figure is the area of water inside that outline, less the area of its islands. The provincial outline is mapped to within a few meters of the shore, and a shoreline measured from a coarser map comes out shorter, which is why a figure published elsewhere is often lower.
Survey coverage: Not every survey covered every arm of a lake, and the province’s index does not always record where a survey ended.
Nearby lakes: Distances are measured between lake centres.
Islands and names: Islands are counted and measured on the Ontario Hydro Network outline; names are the register’s, placed by its own coordinate. The register names islands the outline draws as part of a larger one, and the outline holds islands the register has not named, so the two counts differ. The outline carries some lakes across marsh, so a gap in the marsh is drawn as land, and every such gap is included in the island count. Where the register has not named one and it lies mostly inside a wetland in the province’s Wetland With Significance dataset, the page names the wetland and the table of largest islands leaves it out. Wetland boundaries are mapped at their own scale and can cover a small island whole.
Depth contours: Each contour is drawn where the survey placed it, at the survey’s own positional accuracy. The survey carries its own shoreline, which differs from the Ontario Hydro Network’s outline, so a contour near the shore can run to or past the outline. Such a stretch is drawn along the outline, as a drawing convention, and is not the survey’s line there. The contour count in the stat band is the province’s, and it includes the survey’s own shoreline contour, one ring around the mainland and one around each charted island, which the map leaves off; the map’s small print gives the split.
Location: Municipal boundaries are read from the province’s records as published and can lag a boundary change.
Fish: Ontario’s fish records are compilations of existing knowledge from field biologists and do not represent exhaustive inventories. A species that is not listed was not ruled out. The species list carries one date for the whole record and none for any species.
Stocking: A stocking record is a release on a date. It says nothing about how many fish survived or about the population in the lake today.
Eating advice: The guide’s advice is for fish taken from the lake at the tested location and applies to the size classes tested. The province’s guide is the authority and is updated each year.
Fishing rules: Seasons and limits are the zone’s, for the year of the dataset the page was built from, and a licence’s own conditions and any waterbody exception apply over them. The province’s regulations summary is the authority.

Where these figures come from

Depth, shoreline, islands and named places: Ontario Ministry of Natural Resources bathymetry and the Ontario Hydro Network, © King’s Printer for Ontario, Open Government Licence – Ontario.
Aerial photography: Ontario Imagery Web Map Service, Open Government Licence – Ontario, drawing this frame from North Western Ontario Orthophotography Project 2022, Northwestern Ontario Orthophotography Project 2017, Forest Resource Inventory T2 (T2) 2018-2027, Forest Resources Inventory 2007-2011 and Sentinel 2 2025, satellite.
Official names: Geographic Names Ontario, Ministry of Natural Resources, Open Government Licence – Ontario. Marinas: Overture Maps Foundation places data, CDLA-Permissive 2.0.
Lake outline and municipal boundaries: Ontario Hydro Network and Ontario municipal boundary records, Ministry of Natural Resources, Open Government Licence – Ontario.
Fish species and thermal regime: Ontario Aquatic Resource Area records. Spawning areas: Ontario Fish Activity Area records. Both Ministry of Natural Resources, Open Government Licence – Ontario.
Stocking: Historical Fish Stocking Data and Fish Stocking Data for Recreational Purposes, Ministry of Natural Resources, Open Government Licence – Ontario.
Consumption advice: Guide to Eating Ontario Fish advisory database, 2025 edition, Ministry of the Environment, Conservation and Parks, Open Government Licence – Ontario.
Seasons and limits: Ontario recreational fishing regulations data, Ministry of Natural Resources, Open Government Licence – Ontario.
Fish plates: Duane Raver, U.S. Fish and Wildlife Service; Ellen Edmonson and Hugh Chrisp, New York State Conservation Department; Timothy Knepp, U.S. Fish and Wildlife Service; U.S. Fish and Wildlife Service. All public domain.