Booking odds · December
Mammoth Campground (Yellowstone) in December: How Hard Is It to Book?
Mammoth Campground (Yellowstone) · WY · Yellowstone National Park
The verdict
Booking difficulty 2 out of 10. Usually available — you can often book close to your trip.
December rarely sells out — you can often book close to your trip.
Mammoth Campground (Yellowstone) in December scores 2 out of 10 for booking difficulty — easy. Usually available — you can often book close to your trip.
Based on the last 1 year of reservation history, with the campground running roughly 2% full that month. The lightest arrival day is Wednesday, so shifting to a midweek start is the single easiest way to improve your odds.
How far ahead people book
Weekend vs. weekday demand
Best odds: arrivals are lightest on Wednesday in December. A midweek arrival is your easiest booking.
When December reservations open
Reservations for Mammoth Campground (Yellowstone) in December 2026 operate on a rolling 6-month window releasing at 7:00 AM ET.
December 1 stays open
June 1, 2026
at 7:00 AM ET
Release style
6-Month Rolling Window
Releases daily 6 months ahead at 7:00 AM ET
Campsites for December 1, 2026 become bookable on June 1, 2026 at 7:00 AM ET. Each subsequent date throughout December releases day-by-day exactly 6 months prior to arrival.
Facility note: Standard Recreation.gov 6-month rolling window: sites become bookable 6 months before arrival at 7:00 AM ET.
How much does it cost to camp at Mammoth Campground (Yellowstone)?
The camping fee in Mammoth Campground is $25 per night per site.
Fee details as listed on Recreation.gov. Rates and passes change by season, so confirm the current price on Recreation.gov before you book.
Mammoth Campground (Yellowstone) in December: common questions
- How hard is it to book Mammoth Campground (Yellowstone) in December?
- Mammoth Campground (Yellowstone) rates 2 out of 10 for December — Easy. Usually available — you can often book close to your trip.
- When do December reservations open for Mammoth Campground (Yellowstone)?
- Reservations for Mammoth Campground (Yellowstone) in December 2026 open on a rolling 6-month window. Sites for December 1 become bookable on June 1, 2026 at 7:00 AM ET, with each subsequent day releasing day-by-day 6 months ahead.
- What is the best day to arrive at Mammoth Campground (Yellowstone) in December?
- Arrivals are lightest on Wednesday. A midweek arrival is usually the easiest booking.
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