Natural swimming hole
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
Can you swim in Flathead Lake (Big Arm)?
Yes — Flathead Lake (Big Arm) is listed as a natural swimming spot in Montana. Reported water temperature: 65. Heads-up: No lifeguard; cold deep water. There are rarely lifeguards at natural swimming holes — verify conditions locally before you go.
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.