USDA Forest Service · California
Obsidian Flat
USDA Forest Service · California, United States
- Sites
- 1
- Hookups
- 1 no hookups
- Season
- June 15 to September 30
- Cost
- $20 dollars per night
- Max RV length
- 40 ft
- Group sites
- Yes
- Drinking water
- No
- Restrooms
- Yes
- Elevation
- 7,743 ft
- Dark sky
- Bortle class 1
- Cell coverage
- Verizon weak · AT&T good · T-Mobile none (carriers' 4G LTE filings to the FCC, 2025-12; not measured here)
- Access road
- GLASS SPUR A (NFSR 02S23A) · native material · high clearance vehicles
- Lake
- Inyo National Forest
- Nearest town
- LEE VINING
- Address
- BOX 429, LEE VINING, CA, 93541
- Phone
- 760-647-3045
- Activities
- Camping, Hiking, Off Highway Vehicle Trails, Wildlife Viewing
1 numbered sites are mapped one by one - open the site map to pick yours.
About
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.
Contact Info
Between 05/01/2025 and 09/30/2025 this location is staffed. Please call (760) 647-3044 to speak with local staff. From 10/01/2025 to 04/30/2026 this location is unstaffed. Please call (760) 647-3005 for general information.
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
Weather, month by month
| Month | Typical high | Typical low | Coldest night | Hottest day | Years with a night below 32°F |
|---|---|---|---|---|---|
| January | 36° | 17° | -2° | 48° | 11 of 11 |
| February | 36° | 16° | 1° | 51° | 11 of 11 |
| March | 37° | 19° | 0° | 60° | 11 of 11 |
| April | 44° | 24° | 6° | 57° | 11 of 11 |
| May | 56° | 33° | 15° | 69° | 10 of 11 |
| June | 70° | 44° | 27° | 82° | 2 of 11 |
| July | 80° | 52° | 43° | 87° | 0 of 11 |
| August | 77° | 51° | 43° | 85° | 0 of 11 |
| September | 69° | 45° | 36° | 78° | 0 of 11 |
| October | 60° | 37° | 16° | 74° | 7 of 10 |
| November | 49° | 30° | 8° | 67° | 10 of 10 |
| December | 38° | 19° | 1° | 54° | 10 of 10 |
Mid-month figures from 2016–2026 of daily weather at this spot (ERA5 reanalysis via Open-Meteo, CC BY 4.0), in °F. Typical is the median; coldest and hottest are the extremes seen.
Nearby campgrounds
- Deadman Campground, Upper And Lower · USDA Forest Service · 1 mi
- Upper Deadman Campground · USDA Forest Service · 1 mi
- Glass Creek Campground · USDA Forest Service · 1 mi
- Hartley Springs Campground · USDA Forest Service · 3 mi
- Big Springs Campground · USDA Forest Service · 4 mi
All public campgrounds in California · Every state and province · Facts read from the operator 2026-02-25. Confirm fees, rules and current status with the operator before you go.