Mount Diablo State Park

Clayton, California · Campsite openings, cancellations & sold-out date alerts

State ParksMedium parkWatched around the clock

Weekend availability

Live from ReserveCalifornia · checked Sep 13, 8:45 AM PT

Sold out 5 of the next 6 weekends — exactly when cancellation alerts earn their keep.

  • Fri, Sep 18
    Limited
    1/3 campgrounds
  • Fri, Sep 25
    Sold out
  • Fri, Oct 2
    Sold out
  • Fri, Oct 9
    Sold out
  • Fri, Oct 16
    Sold out
  • Fri, Oct 23
    Sold out
Alert me when a sold-out weekend opens

Sold out for your dates? We'll tell you the second a site opens.

Cancellations at Mount Diablo State Park get rebooked in minutes. We check ReserveCalifornia around the clock and alert you before the crowd refreshes the page.

Set an alert for Clayton$9.99/mo — why we charge

Not ready to subscribe? Get a free weekend heads-up.

We'll email you if Mount Diablo State Park opens up for a weekend you pick. No account needed.

How booked is Mount Diablo State Park?

as of July 23

Weekends book out well ahead here — 1 of the 3 Saturdays we sampled, as far out as Jan 2027, are already sold out. When a site frees up it's gone again within minutes, so people watch Mount Diablo State Park and hear the instant one opens for their dates. Weekdays still have room — for now.

Weekends (Saturday night)

Aug 8Sold out
Oct 24Open
Jan 9Open

Weekdays (Wednesday night)

Aug 19Open
Nov 4Open

Availability checked directly against the reservation system, out to 6 months ahead.

Park type

State Parks

Medium park

Online booking

Available on ReserveCalifornia

Official state reservation system

Alert coverage

Checked around the clock

Openings, cancellations & new dates

Facilities

8

Campsites

200

Miles of trail

15

Restroom facilities

Facility counts reported by California State Parks district staff.

RV camping at Mount Diablo State Park

Straight from ReserveCalifornia's campsite catalog — not estimates.

RV-suitable sites
46
Max rig length
20 ft

RV and hookup sites are the first to sell out — set an alert with your rig length and we'll ping you the second a matching site opens. Watch this park →

Why campsites open up at Mount Diablo State Park

California's refund rules create a predictable wave of cancellations. Because campers lose money if they cancel late, most drop their reservations right before the refund deadline — which means openings cluster about a week out from any given date.

If they cancel…They get back
7+ days before arrivalFull site fees refunded, minus the cancellation fee
2–6 days beforeFirst night's fee forfeited; the rest refunded, minus the fee
Under 2 days / no-showNo refund — all fees forfeited

Source: California State Parks camping policies (refund schedule for arrivals on or after July 1, 2026).

How booking Mount Diablo State Park works

  • Sites are reservable up to 6 months ahead on a rolling window — each new date opens exactly six months out.
  • New inventory releases every morning at 8:00 a.m. Pacific Time.
  • There is no waitlist — a cancelled site just reappears in search, first-come, first-served.
  • Have your login and payment saved so you can book in under a minute when your alert lands.

Source: ReserveCalifornia FAQ (California State Parks).

Where Mount Diablo State Park is

96 MITCHELL CANYON RD

Clayton, CA 94517

37.8520, -121.9255

Get directions

Getting a campsite at Mount Diablo State Park

How do I get a campsite at Mount Diablo State Park when it's sold out?

Cancellations happen constantly — the trick is being first to know. Set an alert for your dates and we'll watch Mount Diablo State Park on ReserveCalifornia around the clock, then notify you the moment a site opens. Alerts run on a Pro subscription ($9.99/mo, cancel anytime).

How far ahead can I book Mount Diablo State Park?

California State Parks campgrounds, including Mount Diablo State Park, are reservable up to 6 months in advance on a rolling daily window — each new date becomes bookable exactly six months out, released at 8:00 a.m. Pacific Time. Peak summer and holiday dates at popular parks can sell out within minutes of release.

When do campsites usually open up at Mount Diablo State Park?

Openings are driven by California's cancellation policy. Campers get a full refund (minus the fee) only if they cancel 7+ days before arrival; cancel 2–6 days out and they forfeit the first night; under 2 days there's no refund. That refund cliff produces a predictable wave of cancellations around 7 days before a date — the best window to catch an opening at Mount Diablo State Park.

Does ReserveCalifornia have a waitlist for Mount Diablo State Park?

No. ReserveCalifornia has no waitlist or notification feature. When a site at Mount Diablo State Park is cancelled it simply returns to inventory at full price, first-come, first-served — whoever books it first gets it. That's exactly why an alert service exists.

Where do I book a campsite at Mount Diablo State Park?

Reservations for Mount Diablo State Park are made on ReserveCalifornia, the official booking system for California State Parks. GetParkAlerts is independent — we tell you when a site opens; you book it directly on the official site.

Parks near Mount Diablo State Park

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