How campsite availability works

A campsite calendar answers one question: can this site be booked for these nights right now? The answer comes from rules the reservation system applies before it shows you anything. This reference documents those rules for five systems, with the official source and the date each rule was checked.

Four rules decide what the calendar shows

A search that returns nothing has usually hit one of these four. The dates may not be released yet. Every site may be reserved. The nights may be empty but too few to meet a weekend minimum. Or the campground may hold its sites for walk-up campers and never list them online.

The five systems at a glance

BC Parks is included in the comparison tables on the booking windows and cancellations pages. It opens frontcountry sites three months before arrival at 7 a.m. Pacific.

Rolling windows and launch days

Reservation systems release inventory in one of three ways.

Rolling daily window. Each morning, one more arrival date becomes bookable. ReserveCalifornia, Ontario Parks, BC Parks and Indiana's ReserveAmerica site work this way. The window is counted in calendar months, so the release date normally has the same day number as the arrival date.

Monthly block. A month of arrival dates opens at once. Five Yosemite campgrounds on Recreation.gov release this way on the 15th of each month, five months ahead.

Annual launch. A park's entire season opens at a single published date and time. Parks Canada uses this model and sets a separate launch for each park.

The release model matters more than the length of the window. Under a rolling window the busiest moment for any date is one specific morning, and it can be calculated. Under an annual launch, the whole season is contested in the first hour and the date changes every year.

What happens after the first release

Reservations get cancelled, shortened and changed, and those nights return to the calendar. Only one of the systems covered here publishes a time for that. In California state parks, a cancelled site usually stays off the calendar overnight and goes back on sale at 8 a.m. the following day, according to the agency. Recreation.gov, Parks Canada, Ontario Parks and BC Parks publish refund deadlines and fees but no return time.

Some systems also lock new bookings for a period. Ontario Parks freezes every reservation until four months before its arrival day: no change, no cancellation. Indiana freezes changes and cancellations for 18 days on any reservation that reaches past the edge of the booking window, and Recreation.gov blocks changes to such a reservation for the same 18 days. Nights under one of these locks stay off the calendar until the lock ends.

How to read this reference

• Times are given in the reservation system's own time zone.
• "Checked" dates are the day a rule was last compared with the official page. Agencies change policies between seasons, and individual campgrounds can override a system-wide rule.
• Where an agency has not published a rule, the page says so. Nothing here is estimated from observed behaviour.
• The official booking site is the authority for a specific campground. Use this reference to know which rule to look for and where the agency states it.

Who publishes this

Campsite Availability is published by OpenCampsite, a service that watches booked campgrounds and notifies campers when a matching site opens. The rules documented here are the ones that service has to follow. More detail is on the About page.