Flathead Lake (Big Arm)
Lake · Montana
About this swimming hole
The Big Arm unit of Flathead Lake State Park on the lake's west side, with a long pebble beach popular with sunbathers and swimmers. Camping under ponderosa pine and juniper is a major draw, with trails above the bay. Like the rest of Flathead Lake, the water is clear and cold year-round.
Good to know
| Water type | Lake |
|---|---|
| Water temperature | 65 |
| Depth | Deep lake; pebble beach entry |
| Best season | June-September |
| Fees | MT state park day-use fee |
| Reservations required | No |
| Hours | Day use |
| Parking | Day-use parking |
| Amenities | Campground, hiking trail |
| County | Lake County |
| Nearest town | Big Arm |
| Safety notes | No lifeguard; cold deep water |
Map
Official information
Official park / agency page ↗ — check current conditions, fees, and reservations here before you go.
Nearby swimming holes
Frequently asked questions
Does Flathead Lake (Big Arm) require reservations?
No reservations are required at Flathead Lake (Big Arm) based on current information — but verify before you go.
Is there a fee to visit Flathead Lake (Big Arm)?
Reported fee info: MT state park day-use fee. Fees can change — confirm with the official link.
When is the best time to visit Flathead Lake (Big Arm)?
The best season is typically June-September.
⚠️ Verify before you go. Conditions, fees, reservations, and access can change — confirm details with the official link before visiting. Last verified: September 2026