Grassy River

River Northern Ontario FMZ 4 Provincial Park

About this spot

Grassy River is a river in the Northern Ontario area of Ontario, in Fisheries Management Zone 4. This waterbody is inside an Ontario provincial park: a valid Ontario fishing licence is required and park rules apply. Ontario's rivers and streams provide excellent fishing for trout, Pacific salmon, and many other sport fish species.

Location

Fish Species

No species reported for this spot yet.

Fisheries Management Zone 4

Grassy River is in Fisheries Management Zone 4. Open seasons, catch limits and size limits in Ontario are set zone by zone, and some lakes carry their own exceptions, so check the FMZ 4 rules before you fish.

FMZ 4 regulations on ontario.ca

Ice fishing on Grassy River (2026–27)

Ontario has no separate ice fishing season: the regular open seasons apply through the ice. Grassy River is in Fisheries Management Zone 4, where 9 of 13 species groups are open for the whole ice season (December 1 to March 31) under the zone-wide rules.

Species	Through the ice	Zone-wide season	Limits
Brook trout	Part of the season Jan 1 – Mar 31	January 1 to Labour Day	S-5 and C-2; not more than 1 greater than 30 centimetres
Crappie	Open	open all year	S-15 and C-10
Lake sturgeon	Closed	closed all year
Lake trout	Part of the season Jan 1 – Mar 31	January 1 to September 30	S-2; not more than 1 greater than 56 centimetres, and C-1; no size limit
Lake whitefish	Open	open all year	S-12 and C-6
Largemouth and smallmouth bass combined	Open	open all year	S-2 and C-1; must be less than 35 centimetres from January 1 to June 30 and December 1 to December 31, S-4 and C-2; no size limit from July 1 to November 30
Muskellunge	Part of the season Dec 1 – Dec 15	third Saturday in June to December 15	S-1; must be greater than 102 centimetres, and C-0
Northern pike	Open	open all year	S-4 and C-2; none between 70-90 centimetres, not more than 1 greater than 90 centimetres
Rainbow trout	Open	open all year	S-5 and C-2
Splake	Open	open all year	S-5 and C-2
Sunfish	Open	open all year	S-50 and C-25
Walleye and sauger combined	Open	January 1 to April 14 and third Saturday in May to December 31	S-4 and C-2; not more than 1 greater than 46 centimetres
Yellow perch	Open	open all year	S-50 and C-25

S = sport fishing licence, C = conservation licence (daily catch and possession). Dates are worked out for 2026–27 from the wording of the 2026 summary. Ontario publishes a new summary every January 1, so check the 2027 edition for dates after December 31.

Grassy River is not listed by name in the zone's species or waterbody exceptions or fish sanctuaries. Some exceptions cover whole townships or river systems, so read the zone page before you go.

Ice huts in Zone 4

No hut registration is required in this zone. There is no fixed removal date, but every hut must be off before the ice breaks up. You may fish with two lines through the ice in most waters, within 60 m and in sight of each.

Zone 4 ice fishing rules Ice fishing in Ontario guide

Source: Ontario Fishing Regulations Summary 2026, Zone 4 (ontario.ca); ice hut rules: ontario.ca/page/ice-fishing. This summary is not the law: check the regulations and local conditions, and never go on ice you have not tested.