Duncan Lake
About Duncan Lake
Duncan Lake is a 477-acre lake near Grand Marais in Cook County, Minnesota. It reaches 130 feet at its deepest point, with an average depth of about 47 feet, and has roughly 7.6 miles of shoreline. DNR surveys put average water clarity at about 17.8 feet, which is exceptionally clear for Minnesota. Access is by portage through Superior National Forest; most lakes reached this way lie in or beside the Boundary Waters Canoe Area Wilderness, where an entry permit is required.
Minnesota DNR fisheries surveys list 4 fish species here, including smallmouth bass and lake trout. The most recent fisheries survey on file dates to 2025.
Public access is by portage — plan on a canoe, kayak or small boat you can hand-launch. Duncan Lake #1 and Duncan Lake #3 are mapped close to the shoreline for overnight stays.
Plan Your Visit to Duncan Lake
- 477 acres, up to 130 feet deep, near Grand Marais
- Portage access only — bring a boat you can hand-launch unless you confirm a ramp
- Game fish on the DNR survey: smallmouth bass and lake trout
- Average water clarity around 17.8 feet — very clear
- Camping close to the water at Duncan Lake #1 and Duncan Lake #3
- Boundary Waters country: entry permit required, no cans or glass bottles, and motors are restricted on most lakes
Access & Fees
- Public access
- Portage access only
- Launch fee
- Free at DNR accesses
- Managed by
- US Forest Service
- Wilderness permit
- BWCAW permit required
Conditions
- Surface area
- 477 acres
- Max depth
- 130 ft
- Average depth
- 47 ft
- Shoreline
- 7.6 mi
- Water clarity
- 17.8 ft
- Shallows (under 15 ft)
- 148 acres
Rules & Regulations
- A Minnesota fishing license is required for anglers 16 and older
- Drain plugs must be out and all water drained before leaving any access; remove aquatic plants from boats and trailers
- Children under 10 must wear a life jacket on a boat that is underway
- A trout and salmon stamp is required to fish designated trout lakes or to keep trout
- A BWCAW permit is required year-round; quota permits apply May 1 through September 30
Facilities
- 1 carry-in access
- 1 portage access
- Camping: Duncan Lake #1, Duncan Lake #3, and Duncan Lake #4
Best For
- Lakeside camping
- Canoe tripping
- Ice is never completely safe — check thickness yourself before walking or driving on any lake
Angler's Report
Minnesota DNR LakeFinder- Species on survey
- 4
- Game fish
- 2
- Stocked
- No
- Last DNR survey
- 2025
- Special regulations
- No
- Fishing pier
- No
- Ice fishing
- Yes
- Boat launch
- No
Fishing data: Minnesota Department of Natural Resources. Regulations change — confirm with the current DNR fishing regulations.
Camping & Reservations
Duncan Lake #1, Duncan Lake #3, Duncan Lake #4, and Duncan Lake #9 are mapped on or near Duncan Lake. Minnesota state park sites are booked through the DNR reservation system, national forest campgrounds through Recreation.gov, and most state forest campgrounds are first-come, first-served.
Campground locations © OpenStreetMap contributors. Confirm details with the operator.
Activities
Amenities
Fish Species
Plan your trip to Duncan Lake
Compare Duncan Lake against the top-ranked lakes nearby, then map your route.
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Nearby Lakes
Partridge Lake
47 out of 100 Lake ScoreCook · Grand Marais118 acres
1.1 miles away
Moss Lake
52 out of 100 Lake ScoreCook · Grand Marais254 acres
1.1 miles away
Leo Lake
39 out of 100 Lake ScoreCook · Grand Marais102 acres
1.8 miles away
Rose Lake
51 out of 100 Lake ScoreCook · Maple Hill1,410 acres
2 miles away
Hungry Jack Lake
71 out of 100 Lake ScoreCook · Grand Marais474 acres
2.1 miles away
Bearskin Lake
66 out of 100 Lake ScoreCook · Grand Marais509 acres
2.1 miles away
Frequently Asked Questions
Where is Duncan Lake?
Duncan Lake is in Cook County, Minnesota, near Grand Marais. It covers 477 acres and reaches 130 feet deep.
How big and how deep is Duncan Lake?
Duncan Lake covers 477 acres with about 7.6 miles of shoreline. Its maximum depth is 130 feet and its average depth is about 47 feet.
What fish can you catch at Duncan Lake?
Minnesota DNR surveys list Smallmouth Bass and Lake Trout. A Minnesota fishing license is required for anyone 16 and older.
Is there a public boat launch on Duncan Lake?
Public access is on record, but not a trailer ramp: portage access only.
Can you swim at Duncan Lake?
There is no mapped public swim beach at Duncan Lake. Minnesota's public waters are open to swimming where you have legal access, but there are no lifeguards or water-quality monitoring away from designated beaches.
Is Duncan Lake stocked?
The DNR has no stocking report on file for Duncan Lake; its fishery is sustained by natural reproduction or has not been stocked recently.
Can you camp at Duncan Lake?
Yes. Duncan Lake #1, Duncan Lake #3, and Duncan Lake #4 are mapped on or near the shore. Confirm whether sites are reservable or first-come, first-served before you go.