Openings · last 7 days
1
Booking reality
Campsite Sniper detected 1 site opening here in the last 7 days
01 · Detected Opening History · the openings record · file CS-231955
When Obsidian Flat reopens
Obsidian Flat's openings record: every site-date Campsite Sniper detected turning available, logged and time-stamped. Refreshed hourly.
Openings · last 30 days
8
Openings · last 90 days
8
Only 8 openings in the last 90 days: not enough recent activity for a reliable pattern. A free Campsite Sniper alert watches around the clock instead, and pings you the moment one opens.
02 · Availability Outlook · Sep 18 – Sep 30, 2026 · of 1 monitored site
Of the 13 tracked site-nights (Sep 18 – Sep 30, 2026): 4 open for online reservation · 9 reserved.
Where the open windows are
69.2% of tracked site-nights are not currently open for online reservation. 4 of 13 remain open; here is where they are.
Load status
Sep 18 – Sep 30, 2026Not open online69.2%
Open site-nights4 / 13
Reserved (of online inventory)9 / 13
Weekday openings3
Weekend openings1
Of the open site-nights on mapped sites, 3 fall on weekdays and 1 on weekends (Fri–Sun).
Open dates by month
Sep 2026 – Sep 2026September holds the most room. 4 of 13 site-nights are still open there.
Holiday windows
Sites open per night · of 1 site| Window | Night | Sites open | Status |
|---|---|---|---|
| Labor Day | SAT Sep 5 | 0 | None open |
| SUN Sep 6 | 0 | None open | |
| MON Sep 7 | 0 | None open |
Labor Day: no online availability on any tracked night.
Availability
Most open site-nights · tracked window| Site | Open site-nights |
|---|---|
| 1 | 4 |
This site currently has 4 site-nights available.
Next windows
As of Sep 18, 2026 snapshotNext open dateSun · Sep 20
The next bookable night is Sep 20. Campsite Sniper can watch later dates for you.
Stays and site detail
4 open site-nights across 1 site at Obsidian Flat, from the same hourly snapshot as everything above.
Multi-night stays. 1 2-night, 1 3-night openings where a single site is free for every night, per Campsite Sniper's current snapshot — soonest Sep 20 at site 1.
RV length. Longest recorded site here is 40 ft. 1 site takes 25 ft, 1 site takes 35 ft, 1 site takes 40 ft.
All 1 site with current availability
| Site | Max RV | Hookups | Open site-nights | Longest run | Dates |
|---|---|---|---|---|---|
| 1 | 40 ft | None | 4 | 3 nights | Sep 20, Sep 21, Sep 22, Sep 30 |
About Obsidian Flat
Overview
Obsidian Flat Group Campground, located just outside of Mammoth Lakes, California, provides an opportunity for a group to enjoy a secluded getaway in the eastern Sierra Nevada Mountains. With a peaceful forested setting and mountain views, the campground's location is perfect for relaxing and spending time in nature.
The area is popular for exploring the surrounding forest and geology, as well as nearby hiking, bicycling, fishing and off-road vehicle riding options.
Recreation
The eastern Sierras are known for their exceptional trout fishing. Campers can try their luck in Deadman Creek.
The majestic scenery and challenging trails are an obvious draw for hikers, mountain bikers and off-road vehicle enthusiasts. Deadman Creek Trail leads hikers into the spectacular Ansel Adams Wilderness.
Facilities
One group camping area can accommodate one group of up to 50 people, and up to five RVs (up to 40 feet in length) or 15 vehicles at a time. The site is fairly primitive and is equipped with a picnic table, vault toilet, campfire ring and bear-proof locker for food storage.
Natural Features
The campground is named after an obsidian lava flow nearby. It is situated in a pine forest at an elevation of 7,800 feet. Deadman Creek is adjacent to the facility, and several lakes are down the road.
Many species of wildlife call the mountains home, such as black bear, mountain lions, mule deer, pine marten, pika and numerous fish and birds.
Nearby Attractions
Hikers can access the scenic Ansel Adams Wilderness via nearby trails, and Yosemite National Park is a great day trip.
Ansel Adams Wilderness
Yosemite National Park
1 monitored siteRVs up to 40 ftNo hookupsMax party 50
Getting there
Heading North From U.S. Highway 395 and State Highway 203 (Mammoth Lakes Junction), travel 8.2 miles north on 395. Turn west onto Deadman Road and follow for 3.2 miles to Upper Deadman Campground. Turn toward the Group Campground turnoff onto FS Road 2S05F. Continue one mile to the campground on the right. Heading South From U.S. Highway 395 and State Highway 158 (June Lake Jucntion South) travel approximately 6.5 miles south on 395 and turn right onto Deadman Road and follow for 3.2 miles to Upper Deadman Campground. Turn toward the Group Campground turnoff onto FS Road 2S05F, across the road. Continue one mile to the campground on the right.
Box 429, Lee Vining, CA 93541760-647-3045
CampingHikingOff Highway Vehicle TrailsWildlife Viewing
View on Recreation.gov ↗ Get directions ↗
03 · Field Photos · roll CS-231955 · facility
Photo gallery
Roll CS-231955 · Obsidian Flat · Lee Vining CA4 frames · facility
FAQ
How do I get a reservation at Obsidian Flat?
Reservations for Obsidian Flat are made through Recreation.gov. 4 of 13 tracked site-nights are currently open (30.8%). Campsite Sniper has also detected 8 site openings here in the last 90 days, so further dates may appear. Pick a site on the map to see its calendar, or set a free Campsite Sniper alert. You complete the reservation yourself on Recreation.gov.
Does Campsite Sniper book this campground for me?
No. Campsite Sniper sends alerts and direct Recreation.gov links. It never books, pays for, holds, hoards, or resells reservations.
How current is this availability data?
Campsite Sniper re-checks public Recreation.gov availability for this facility every hour and republishes whenever anything changes. This facility's data last changed at Sep 18, 2026 16:19 UTC; an older timestamp means nothing has changed since that time, not that checking stopped. Always confirm final availability on Recreation.gov when you book.
How often do new openings appear at Obsidian Flat?
Campsite Sniper detected 1 site-date opening at Obsidian Flat in the last 7 days, 8 over 30 days and 8 over the last 90.
Can I get a multi-night stay at Obsidian Flat?
1 three-night opening is showing, counting only runs where the SAME site is free for all three nights. The soonest starts Sep 20 at site 1. Confirm and book on Recreation.gov.
Which sites at Obsidian Flat fit a 35-foot RV?
1 of the 1 site that support RV analysis has a recorded maximum of 35 ft or more; the longest recorded is 40 ft.
Which month has the most availability at Obsidian Flat?
September 2026, with 4 open site-nights in the current snapshot of 13.
When is the next open date at Obsidian Flat?
As of the Sep 18, 2026 snapshot: the next open date is Sun, Sep 20. Detected openings can add earlier dates at any time; a free Campsite Sniper alert catches those the moment they appear.
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