Flathead Lake Fishing Guide
Flathead Lake fishing today centers on lake trout, lake whitefish and yellow perch, three nonnative species that are now prominent in the lake, according to the Flathead Lake Biological Station. The rules depend on where you fish. The northern part of the lake falls under Montana FWP regulations. The southern part lies within the Flathead Indian Reservation, where a tribal permit is required. Lakes in FWP's Western District, including Flathead Lake, are open all year. This guide covers the species, the 2026 FWP limits for the lake, licenses and the bull trout rule every angler needs to know.
What fish are in Flathead Lake?
FLBS says Flathead Lake originally supported 11 native fish species, and that fish introduced since the late 1800s, along with the arrival of nonnative Mysis shrimp in the mid-1980s, changed the lake's food web. Today lake trout, lake whitefish and yellow perch are prominent ( FLBS lake facts).
| Species | Native or introduced | What anglers should know |
|---|---|---|
| Lake trout | Introduced (1905) | Abundant and expanding, per FLBS. FWP sets a high daily limit on the northern part of the lake (see below). |
| Lake whitefish | Introduced (1890) | Abundant and expanding, per FLBS. |
| Yellow perch | Introduced (1910) | No overall limit on the northern part of the lake; only 10 daily over 10 inches. |
| Mountain whitefish | Native | Found in lakes, rivers and streams throughout the basin. |
| Westslope cutthroat trout | Native | Montana's state fish. Catch-and-release only on the northern part of the lake. |
| Bull trout | Native | Listed under the Endangered Species Act. Closed to intentional fishing on Flathead Lake. |
| Northern pike | Introduced (1960s) | Present in Flathead Lake, per FLBS. |
Introduction years and status are from the FLBS fish table.
Flathead Lake fishing regulations (2026)
FWP lists Flathead Lake north of the Flathead Indian Reservation boundary as an exception to the Western District standard rules ( 2026 Montana Fishing Regulations, p. 31):
- Lake trout: 100 daily and in possession, only 1 over 36 inches, and all fish 30 to 36 inches must be released.
- Yellow perch: no limit, but only 10 daily over 10 inches. No possession limit.
- Cutthroat trout: catch-and-release.
- Other species: Western District standard limits apply to species not listed in the exception (p. 23). For example, the standard whitefish limit is 20 daily and 40 in possession.
- Season: Western District lakes and reservoirs are open all year (FWP regulations).
These regulations run from March 1, 2026 through February 28, 2027. Check the current booklet on the FWP regulations page before every trip.
Can you fish for bull trout in Flathead Lake?
No. FWP closes all Montana waters to angling for bull trout, and any bull trout caught must be released without delay, except in specifically authorized waters. For 2026 those are Lake Koocanusa, and Hungry Horse Reservoir with part of the South Fork Flathead River, each requiring a free catch card. Flathead Lake is not one of them. Federal rules also prohibit attempting to take bull trout unless state or tribal regulations specifically authorize it ( 2026 regulations, pp. 13 and 23). Learn to tell bull trout from lake trout before you keep a fish. The regulations booklet includes an identification guide.
Do you need a license to fish Flathead Lake?
Yes, for anyone 12 or older. FWP says most anglers need a conservation license and a base fishing license, plus the Angler Aquatic Invasive Species Prevention Pass, which is required for everyone who fishes in Montana. Anglers 11 and younger need no license but must follow all limits. Nonresidents can buy a full-season license or a short-term license for 1 day or 5 consecutive days ( FWP fishing license basics). Licenses are sold through FWP online licensing.
Do you need a tribal permit to fish Flathead Lake?
On the southern part of the lake, yes. FWP's Flathead Lake regulation notes that a Flathead Indian Reservation tribal permit is required to fish the southern portion, and tells anglers to check tribal fishing regulations for that part of the lake ( 2026 regulations, p. 31). The State of Montana and the Confederated Salish and Kootenai Tribes have a cooperative agreement on the reservation (p. 15). The tribes' Tribal Fish & Game page links the current non-member regulations. Do not assume the FWP limits above apply south of the reservation boundary.
Boats, launches and invasive species
- Inspection: FWP requires watercraft inspections, and all watercraft crossing the Continental Divide into the Columbia River Basin must be inspected before launch (FWP aquatic invasive species; 2026 regulations, p. 21). Nonresidents also need a Vessel AIS Prevention Pass.
- Winter launches: FWP says the West Shore and Yellow Bay units of Flathead Lake State Park have deep-water boat launches that are typically ice-free through winter (West Shore; Yellow Bay).
- Wind and waves: check the NWS Flathead Lake forecast before you head out.
Is there a Flathead Lake fishing report?
We do not publish one. For current conditions, check the NWS lake forecast above and the live water temperature and wind on the FLBS weather center. The FWP regulations booklet also points anglers to FWP's restrictions and closures page for temporary closures not listed in the booklet.
Hiring a fishing charter or guide
Montana licenses fishing outfitters and guides through the Board of Outfitters. Before you book any charter, look up the outfitter's license with the state's licensee lookup. On the southern part of the lake, ask how the charter handles tribal permits. We do not recommend or endorse any charter.
Eating your catch
FWP's sport fish consumption guidelines say contaminants such as mercury and PCBs build up in large predatory fish such as lake trout, while prey fish such as yellow perch carry less. FWP suggests keeping smaller fish to eat and eating big fish less often ( 2026 regulations, p. 20).
Base a fishing trip at The Evergreen
The Evergreen is a six-bedroom, 3.5-bath home in Somers, at the north end of Flathead Lake. The driveway fits three vehicles plus a trailer, so you can tow your own boat and launch at a public ramp or marina. No boat, dock or slip comes with the stay, and the home has no private lake access. After a day on the water, there is a private hot tub and barrel sauna on the deck, and a long dining table for the whole crew.
Rates and availability change by date. The booking page shows live availability and the total for your dates and group size.
FAQ
What fish are in Flathead Lake?
Lake trout, lake whitefish and yellow perch are the most prominent, according to the Flathead Lake Biological Station. Native species include bull trout, westslope cutthroat trout and mountain whitefish.
What is the lake trout limit on Flathead Lake?
On the part of the lake north of the Flathead Indian Reservation boundary, FWP's 2026 limit is 100 daily and in possession, with only 1 over 36 inches, and all lake trout 30 to 36 inches must be released.
Do you need a fishing license for Flathead Lake?
Yes, if you are 12 or older. Most anglers need a Montana conservation license, a base fishing license and the Angler AIS Prevention Pass.
Do you need a tribal permit to fish Flathead Lake?
Yes, on the southern portion of the lake, which is within the Flathead Indian Reservation. Check the Confederated Salish and Kootenai Tribes' current non-member regulations.
Can you fish for bull trout in Flathead Lake?
No. Bull trout are closed to angling on Flathead Lake and must be released without delay if caught.
Is Flathead Lake open to fishing year-round?
Yes. FWP's Western District lakes and reservoirs, including Flathead Lake, are open all year. Limits still apply.
Can we bring a boat to The Evergreen?
Yes. The driveway fits three vehicles plus a trailer. Launch at a public ramp or marina; no boat, dock or slip comes with the stay.
