USGS Streamgage 11264500
Merced River A Happy Isles Bridge near Yosemite, CA
Merced River A Happy Isles Bridge near Yosemite, CA is USGS streamgage 11264500 in California, monitoring river discharge in hydrologic subbasin 18040008. It drains a watershed of about 181 square miles. Discharge records at this site go back to 1915. Typical flow runs near 283.4 cfs in July and 503.5 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- California
- Drainage area
- 181 sq mi
- Gauge elevation
- 4,021 ft
- Subbasin (HUC-8)
- 18040008
- Coordinates
- 37.7313, -119.55902
- USGS site number
- 11264500
- Records begin
- 1915-08-23 (111 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 111 years of data), averaged within each month. These describe the historical normal range — they are not a forecast and not today's reading.
| Month | Low p10 | Typical p50 | High p90 | Range |
|---|---|---|---|---|
| January | 14.4 | 58.9 | 199.8 | |
| February | 34.2 | 92.8 | 202.4 | |
| March | 77.9 | 173.7 | 388 | |
| April | 221.3 | 503.5 | 1,018.7 | |
| May | 467.6 | 1,146.3 | 2,270.3 | |
| June | 277.5 | 1,013.7 | 2,417.3 | |
| July | 67.2 | 283.4 | 1,136.7 | |
| August | 17.2 | 56.5 | 266.1 | |
| September | 5.4 | 17.5 | 84.9 | |
| October | 3.5 | 13.8 | 88.5 | |
| November | 7 | 25.8 | 133.6 | |
| December | 11.2 | 42.9 | 146.9 |
All values in cubic feet per second (cfs).
Common questions
- When does Merced River A Happy Isles Bridge near Yosemite, CA normally run highest?
- May, on the long-term record. The median daily flow that month is about 1,146.3 cfs, against 13.8 cfs in October, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for Merced River A Happy Isles Bridge near Yosemite, CA?
- It depends on the month. In January, half of days historically fall near 58.9 cfs, with the middle 80% of days between 14.4 and 199.8 cfs. The month-by-month table on this page gives the full range.
- How long has Merced River A Happy Isles Bridge near Yosemite, CA been measured?
- Discharge records at USGS site 11264500 begin in 1915, about 111 years, covering roughly 9,126 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Where is Merced River A Happy Isles Bridge near Yosemite, CA?
- The gauge sits at 37.7313, -119.55902, in California, in hydrologic subbasin 18040008, at an elevation of about 4,021 feet, draining roughly 181 square miles.
- Can I use Merced River A Happy Isles Bridge near Yosemite, CA data for flood or safety decisions?
- No. Rivermatics provides estimates, not guarantees, and the readings and forecasts here may be delayed, inaccurate, or wrong. Do not use them for navigation or for any safety, rescue, or emergency decision. Check the National Weather Service and USGS directly, and use your own judgment.