Satellite Depth Map
Click the map to enlarge. The lake runs in a long NW–SE band; two deep basins drop past 30 m, with the boat/canoe access marked at the south end.
Depth shown in metres and feet (see on-map legend). Bathymetry: Géobase des bathymétries de lac du Québec (MELCCFP), via Données Québec. Satellite: Esri World Imagery.
About Lac des Sept Frères
Lac des Sept Frères lies deep inside the Réserve faunique de Papineau-Labelle, in the unorganized territory of Lac-Nominingue (MRC Antoine-Labelle, Laurentides), roughly 35 km southeast of Mont-Laurier. It's a long, narrow lake — about 6.7 km end to end and 3.1 km² — that drains north into Lac Montjoie and on down the Petite-Nation watershed toward the Ottawa River.
The lake is cold and clear, with two basins that drop to about 40 m (131 ft) — cold-water habitat that holds touladi (lake trout, locally "truite grise"). Sept Frères is one of a small cluster of Petite-Nation lake-trout lakes managed and studied together, alongside nearby Lac Montjoie and the better-known Lac Gagnon at Duhamel.
It also holds introduced ouananiche (landlocked salmon), which showed up in the catch around 2000 and now share the lake's rainbow smelt (éperlan) forage with the touladi. Because the lake sits inside a SEPAQ wildlife reserve, fishing is by reservation only — there's no roadside public launch, but the reserve rents canoes right on the lake (see Access).
- TerritoryRéserve faunique de Papineau-Labelle
- Nearest townMont-Laurier (~35 km NW)
- From Ottawa~2h30 drive (via Duhamel)
- Length / area6.7 km · 3.1 km²
- Max depth40 m (131 ft)
- AccessSEPAQ reservation; register at a reserve post
- BoatsReserve canoe rental; gas motors ≤ 15 hp; no personal boats
- Fish speciesLake trout (touladi), ouananiche, rainbow smelt
- OutflowLac Montjoie → Rivière de la Petite Nation
Fishing Regulations
Inside the Réserve faunique de Papineau-Labelle · underlying Québec Zone 10. Wildlife-reserve rules can be stricter than the zone — always confirm current limits with SEPAQ and the Zone 10 summary before you fish.
⚠️ This is a reserve lake, not an open Zone 10 water. The general Zone 10 regulations don't automatically apply inside a réserve faunique: SEPAQ controls access, the season, the number of boats and the catch limits. You must reserve and register before fishing, and a valid Québec fishing licence is still required.
| Species | Season / limit | Notes |
|---|---|---|
| Lake Trout (Touladi) | Reserve sets it · Zone 10 baseline: Apr 23 – Sep 15 | Zone baseline is 1/day, 45 cm minimum, angling only — but this wild population is declining (see Touladi below), so expect SEPAQ to set tighter limits. Consider catch-and-release. |
| Ouananiche (landlocked salmon) | Reserve sets it · Zone 10 baseline: Apr 23 – Sep 15 | Zone baseline is 3/day, angling only. Introduced; appeared in the catch around 2000. Part of the same touladi/ouananiche study. |
| Rainbow Smelt (éperlan) | — | Forage fish, not a target. The food both touladi and ouananiche depend on. |
The figures above are the general Zone 10 baseline (2026–27 season). Inside a réserve faunique, SEPAQ can set shorter seasons and lower limits than the zone, and you are informed of the exact rules when you register. Confirm seasons, limits and size rules with SEPAQ (Papineau-Labelle) and the Zone 10 summary before keeping fish.
Touladi: Status & Conservation
Why the lake-trout here need a careful hand.
Lac des Sept Frères is one of four Petite-Nation lakes — with Lac Gagnon, Lac Simon and neighbouring Lac Montjoie — where the regional wildlife branch has flagged a declining lake-trout population. On Sept Frères, an MFFP status report found far fewer touladi, at every size, than in past surveys.
The leading suspect is competition with the introduced ouananiche, which appeared in the catch around 2000 and feeds on the same rainbow smelt the touladi rely on. Because quota fishing can remove slow-growing fish before they spawn, managers said the sport fishery on the lake would be re-evaluated, with the options on the table ranging from a tighter or closed lake-trout season to restocking.
The practical takeaway for anglers: treat the touladi gently. Consider catch-and-release, handle deep-caught fish carefully, and check the current reserve rules — they may be stricter than the general Zone 10 limits. (See the regional reporting in Le Droit, 2021.)
Access & the Reserve
There's no roadside public launch — this is a controlled-access SEPAQ lake.
Fishing Lac des Sept Frères means going through the Réserve faunique de Papineau-Labelle, the southernmost wildlife reserve in Québec, with more than 700 lakes shared between the Outaouais and the Laurentides. You reserve ahead — either a day of fishing with a boat on a specific lake, or a stay in a cabin or campground — and register at a reserve post on the way in.
The reserve rents canoes right on Lac des Sept Frères (also at Lac Montjoie, Accueil Gagnon and the Lac-Écho campground). To slow the spread of Eurasian milfoil, personal boats are not allowed on the lakes — only canoes, kayaks and inflatables blown up on site — and where motors are permitted they're capped at 15 hp. Day-fishing reservations don't include a motor rental.
Camping in the reserve is lakeside and low-key: serviced-but-rustic sites, a "fishing-and-camping" option at lacs Joinville and Écho, and canoe-in sites on lacs Écho and du Sourd. The Laurentides-side reception is closed, so the nearest staffed entrance is Accueil Gagnon at Duhamel; online or phone reservations are recommended.
- ManagerSEPAQ — Réserve faunique de Papineau-Labelle
- Reservations1 800 665-6527
- Reserve office819 454-2011
- Nearest receptionAccueil Gagnon, Duhamel
- On-lake rentalCanoes (no motor with day fishing)
- BoatsNo personal craft; canoes/kayaks/inflatables OK; motors ≤ 15 hp
- LicenceValid Québec fishing licence required
- Plan aheadsepaq.com — Papineau-Labelle
Trip Tips
🎣 Work the deep basins
The two troughs that drop toward 40 m are the cold-water holding spots for touladi. Troll the drop-offs and the saddle edges; the smelt — and the fish that chase them — move with the thermocline through summer.
🐟 Go easy on the lakers
This is a stressed, wild population under review. Consider releasing your fish, especially the bigger ones, and check whether the reserve has tightened the touladi season or limit this year.
🛶 Reserve first, then register
No walk-up public launch here. Book a day of fishing or a stay through SEPAQ, register at a reserve post (nearest staffed one is Accueil Gagnon, Duhamel), and rent a canoe on the lake — personal boats aren't allowed.
Getting There
From Ottawa–Gatineau, the simplest approach is up Highway 309 through the Lièvre Valley to Duhamel (about 1h45), where Accueil Gagnon (5000 chemin du Lac-Gagnon Ouest) is the nearest staffed entrance to the reserve. From there, gravel reserve roads run north into the Lac-Nominingue sector and to Lac des Sept Frères — figure roughly 2h30 total from Ottawa. Coming from the Laurentides side, Mont-Laurier is about 35 km to the northwest. Reserve and register before you drive in; the on-lake boat and canoe access is at the south end (≈ 46.312, −75.188).