Free Campground Availability Alerts for Sold-Out Campsites
Outdoorithm is a free campsite cancellation alert tool that monitors Recreation.gov, ReserveCalifornia, ReserveAmerica, and other state park systems every 2 minutes. We send instant campground availability alerts via SMS, email, or push so you can book first on the official site.
Important: We don't book campsites for you. We're your early warning system — when a spot opens, we notify you so you can grab it yourself.
Campground availability alerts for Recreation.gov and state parks
Outdoorithm is a free campground availability alert tool that checks Recreation.gov, ReserveCalifornia, ReserveAmerica, and other state park systems every 2 minutes. We send instant campsite cancellation alerts for sold-out parks like Yosemite, Yellowstone, Zion, Big Sur, Lake Tahoe, and hundreds more so you can book directly on the official sites.
- Instant campground cancellation alerts for top destinations including Yosemite, Yellowstone, Zion, Big Sur, and Lake Tahoe.
- Recreation.gov alerts plus state park availability alerts for ReserveCalifornia, ReserveAmerica, Washington, Oregon, Colorado, Texas, and more with SMS, email, and push notifications.
- 2-minute scans catch last-minute campsite cancellations, booking-window drops, and campground availability for tent, RV, cabin, and group sites.
- Free alternative to Campnab, The Dyrt Alerts, and Hipcamp Alerts—keep booking on official park systems with no added fees.
Booking Calculator
Popular campgrounds open reservations months in advance. Our Booking Calculator tells you exactly when reservations open so you can be ready the moment the window unlocks.
- Know your booking window
Find out exactly when reservations open for your trip dates
- Set your alarm
Get calendar reminders so you never miss opening day
Booking Window
Yosemite National Park
How Our Campground Availability Alerts Work
We do the watching. You do the booking. Here's how our free campground availability and campsite cancellation alerts help you land sold-out campgrounds on Recreation.gov and state park systems.
Choose a Campground
Select the campground you want to visit. We support Recreation.gov and many state park systems.
Set Your Dates
Tell us when you want to camp. We'll start monitoring availability for those specific dates.
Get Notified Instantly
When a site opens up, we'll alert you via email, SMS, or push notification within seconds.
Book It Yourself
Click the link in your alert to go directly to the booking page. You complete the reservation on the official site.
Campsites Disappear Fast
When a cancellation opens up a prime campsite, you have minutes — sometimes seconds — before someone else books it. Our alerts give you the edge.
Nearly half of campsite reservations get cancelled
Thousands watch the same popular campgrounds
We scan for openings every two minutes
Notifications sent within seconds of availability
Our job is to find the opening and notify you instantly. Your job is to book it on the official site.
Campground alerts: Outdoorithm vs Campnab, The Dyrt & Hipcamp
Free Campnab alternative with broader state park coverage, SMS/email/push notifications included, and 2-minute scans for Recreation.gov and state park campground availability alerts.
| Feature | Outdoorithm | Campnab | The Dyrt | Campflare | Hipcamp |
|---|---|---|---|---|---|
| Price | FreeForever | $10-50per month | $9-24per scan | Free | Free |
| Scan Frequency | 2 minutes | 4-15 min | 5-60 min | ~45 sec | 15 sec |
| Coverage | 167,000+ campsites | 350,000+ campsites | 4,000 campgrounds | Rec.gov + 23 state parks | Rec.gov + CA |
| Email Alerts | |||||
| SMS Alerts | |||||
| Push Notifications | |||||
| Recreation.gov | |||||
| State Parks | 20+ systems | Many systems | Limited | 23 systems | CA only |
Outdoorithm
Best Coverage- Scan: 2 minutes
- Coverage: 167,000+ campsites
- Email Alerts
- SMS Alerts
- Push Notifications
- State Parks: 20+ systems
Campnab
- Scan: 4-15 min
- Coverage: 350,000+ campsites
- Email Alerts
- SMS Alerts
- Push Notifications
- State Parks: Many systems
The Dyrt
- Scan: 5-60 min
- Coverage: 4,000 campgrounds
- Email Alerts
- SMS Alerts
- Push Notifications
- State Parks: Limited
Campflare
- Scan: ~45 sec
- Coverage: Rec.gov + 23 state parks
- Email Alerts
- SMS Alerts
- Push Notifications
- State Parks: 23 systems
* Data verified from competitor websites as of December 2025. Features and pricing may change.
Popular Camping Destinations
Set up free alerts for the most popular campgrounds in the country. Get notified when cancellations open up your perfect spot.
National & State Parks
Alerts by State
We're Your Lookout, Not Your Booking Agent
Outdoorithm is a notification service. We monitor campground availability and alert you when spots open up. The actual booking? That's all you.
What Outdoorithm Does
- Monitor 167,000+ campsites across the country
- Check for availability every 2 minutes, 24/7
- Send instant alerts via email, SMS, or push notification
- Include a direct link to the booking page in every alert
What Outdoorithm Does NOT Do
- Make reservations on your behalf
- Hold or reserve campsites for you
- Charge booking fees or commissions
- Guarantee you'll get the site (speed matters!)
Think of us as your 24/7 campsite spotter. When opportunity knocks, we make sure you hear it — but you're the one who answers the door.
Frequently Asked Questions
Everything you need to know about our free campground availability alerts.
Our system automatically checks campground availability every 2 minutes across 167,000+ campsites. When a reservation is cancelled and a site becomes available that matches your alert criteria (dates, campground, etc.), we instantly notify you via email, SMS, or push notification so you can book it before anyone else.
Still have questions? Contact our support team
Ready to Stop Missing Out on
Perfect Campsites?
Set up your free alerts today. We'll watch for openings and notify you the moment a spot becomes available. You handle the booking on the official site.
Remember: We notify. You book directly on Recreation.gov or the park's official website.