Natural swimming hole
Millersylvania SP (Deep Lake)
Lake · Washington
About this swimming hole
Millersylvania State Park's Deep Lake offers calm swimming and paddleboarding minutes from Olympia, with a historic CCC-era bathhouse and a lakeside beer garden in summer. Old-growth forest rings the shore. It is the capital area's classic lake park.
Good to know
| Water type | Lake |
|---|---|
| Water temperature | 60s-70s in summer |
| Depth | calm lake; swim and paddle |
| Best season | June-September |
| Fees | $10 day use (Discover Pass) |
| Reservations required | No |
| Hours | 8am-dusk |
| Parking | lot near the lake |
| Amenities | restrooms, picnic tables, campground, beer garden |
| County | Thurston County |
| Nearest town | Olympia |
| Safety notes | no lifeguard; boat traffic |
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 Millersylvania SP (Deep Lake)?
Yes — Millersylvania SP (Deep Lake) is listed as a natural swimming spot in Washington. Reported water temperature: 60s-70s in summer. Heads-up: no lifeguard; boat traffic. There are rarely lifeguards at natural swimming holes — verify conditions locally before you go.
Does Millersylvania SP (Deep Lake) require reservations?
No reservations are required at Millersylvania SP (Deep Lake) based on current information — but verify before you go.
Is there a fee to visit Millersylvania SP (Deep Lake)?
Reported fee info: $10 day use (Discover Pass). Fees can change — confirm with the official link.
When is the best time to visit Millersylvania SP (Deep Lake)?
The best season is typically June-September.