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
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.
⚠️ Verify before you go. Conditions, fees, reservations, and access can change — confirm details with the official link before visiting. Last verified: September 2026