Gem Lake reservoir
Gem Lake
Gem Lake is a small, high-altitude body of water located in the Sierra Nevada Mountains of California, near Mammoth Lakes. The lake was formed by glacial activity during the last Ice Age, and is fed by several snowmelt streams and small springs. The surrounding area is home to a variety of wildlife, including black bears, mule deer, and mountain lions. There are several hiking trails leading to and around the lake, making it a popular destination for outdoor enthusiasts. The area is also used for recreational activities such as fishing and camping. In addition, the water from Gem Lake is used for irrigation purposes by nearby agricultural operations.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Gem Lake -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Mf San Joaquin R Nr Mammoth Lakes Ca | 557 cfs | → |
| Deadman C A Big Springs Nr Crestview Ca | 33 cfs | → |
| Hot C A Flume Nr Mammoth Lakes Ca | 58 cfs | → |
| Merced R A Happy Isles Bridge Nr Yosemite Ca | 1,750 cfs | → |
| Merced R A Pohono Bridge Nr Yosemite Ca | 2,070 cfs | → |
| Green Creek Near Bridgeport | 49 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Gem Lake.
⚓ Boat launches
- Gull Meadows Car Top Boat Launch
- Navy Beach Paddle Boat Launch
- Lake Edison Boating Site
- Mammoth Pool Rd, California
⛺ Campgrounds
- Silver Lake - June Lake
- Reversed Creek Campground
- Reversed Creek
- Gull Lake Campground
- Gull Lake
- Aerie Crag Picnic Area
🎣 Fishing spots
More fishing →🛶 Paddle runs
- Headwaters At Thousand Island Lake To Agnew Meadows
- Headwaters To Wilderness Boundary
- Headwaters To Walker Lake
- Confluence With Glass Creek To Big Springs
- National Monument Boundary To Soda Springs Footbridge In Devils Postpile National Monument
- Agnew Meadows To Soda Springs Footbridge
🛡 More reservoirs
More reservoirs →Track Gem Lake in the Snoflo app
Save this reservoir as a favorite and set push alerts when storage crosses a threshold (e.g. "alert me at 80% of normal").
About Gem Lake
Where does the data for Gem Lake come from?
Daily storage, pool elevation, and release rates are sourced from USGS, USBR, and USACE monitoring stations. Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
Storage observations are updated daily by the operating agency. The 15-day weather forecast refreshes throughout the day. Snoflo caches and renders the most recent observation -- check the "as of" timestamp on the storage card.
What does the Hazard hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this reservoir, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Gem Lake.