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Map of Flathead Lake - Goose Island
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IntermediateBoat entry

Flathead Lake - Goose Island

Montana, United States
Open Water suggested6–31 m depthBoat entry

Boat dive — see Entry & access.

Flathead Lake - Goose Island at a glance

Flathead Lake - Goose Island is an intermediate boat dive site in Montana, United States with depths of 6–30.5 m (20–100 ft). Typically most favorable Mar–Apr · from 3 years of archive data. Divers commonly see Lake whitefish, Yellow perch, and Lake trout (mackinaw). Check the latest conditions and entry details before you go.

Wind model · graded 13h ago
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Tap a factor for its source and model point

Site hazards: Deep water and steep rock walls; cold thermocline; altitude dive profile; boat traffic in summer.

Read the full hazards ↓

Dive windows this week

Best: Mon
Fri8:00–20:00
Sat8:00–20:00
Sun8:00–20:00
Mon8:00–20:00
Tue8:00–20:00
Wed8:00–20:00
Thu—

Favorable windowModerate window— no window

First light 6:37 · Sunrise 7:09 · Sunset 19:57

Source: Open-Meteo wind · graded 13h ago

Forecast only — always assess conditions on site.

Recent diver reports

Dated firsthand observations from divers — not current conditions.

No diver reports for this site yet. — one dated observation helps every diver after you.

Dived here today — did the forecast match?

What Divers Say

Known for: Lake whitefish, Yellow perch, Lake trout (mackinaw)
Best time: Summer for warmest surface water and best visibility.

Based on community reviews and site data. Conditions vary — always verify before diving.

Best months, historically

What conditions have historically been typical at this site, month by month — not a forecast.

  1. Jan100% 5 kn
  2. Feb98% 7 kn
  3. Mar100% 7 kn
  4. Apr100% 7 kn
  5. May99% 7 kn
  6. Jun96% 7 kn
  7. Jul100% 7 kn
  8. Aug98% 7 kn
  9. Sep99% 7 kn
  10. Oct96% 7 kn
  11. Nov98% 7 kn
  12. Dec94% 6 kn

January, March, April, and July havetypically had the largest share of favorable days here. Conditions vary year to year — this is historical context, not a forecast.

Based on 3 years of archive data. Bar height shows the share of days each month whose conditions have historically scored favorably.

Marine life seen at this site

Species noted at this site — not a promise of what you’ll encounter.

Species seen here

Fills & rentals nearby

No dive shops mapped within 25 km. Know one? Add it to the map.

Data updated June 2026

Site details

The largest natural freshwater lake in the western U.S., Flathead Lake offers clear water with visibility often exceeding 100 feet and depths over 300 feet, drawing divers to its rock formations and underwater cliffs. Goose Island, a glacial rock outcropping ringed by boulders and fish, is a highlight, and several boats have been deliberately sunk to create fish habitat and dive attractions. Somers Bay on the north end holds the upside-down hull of the Kee-O-Mee, a 54-foot pleasure boat that sank in 1937, along with the remains of the old Somers Mill.

boatpinnaclewallwreck

Deep water and steep rock walls; cold thermocline; altitude dive profile; boat traffic in summer.

Reviews

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