USGS Streamgage 11421770
Bear River below Drum Afterbay near Blue Canyon, CA
Bear River below Drum Afterbay near Blue Canyon, CA is USGS streamgage 11421770 in California, monitoring river discharge in hydrologic subbasin 18020126. It sits on the Bear River, alongside 4 other gauges Rivermatics tracks on the same river. It drains a watershed of about 12 square miles. Discharge records at this site go back to 1966. Typical flow runs near 11 cfs in July and 10.9 cfs in April, with the higher of the two arriving in July.
Gauge details
- State
- California
- Drainage area
- 12 sq mi
- Subbasin (HUC-8)
- 18020126
- Coordinates
- 39.25434, -120.77494
- USGS site number
- 11421770
- Records begin
- 1966-04-02 (60 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 60 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 | 5.2 | 6.2 | 11 | |
| February | 5.2 | 6.5 | 22.9 | |
| March | 6 | 10.9 | 40.3 | |
| April | 5.9 | 10.9 | 49.3 | |
| May | 5.8 | 11 | 17.4 | |
| June | 6 | 11 | 12.7 | |
| July | 6 | 11 | 12.6 | |
| August | 6.2 | 11 | 13 | |
| September | 6.1 | 11 | 13 | |
| October | 5.2 | 6.3 | 9.6 | |
| November | 5.1 | 6.2 | 9.1 | |
| December | 5.1 | 6.2 | 8.9 |
All values in cubic feet per second (cfs).
Common questions
- When does Bear River below Drum Afterbay near Blue Canyon, CA normally run highest?
- May, on the long-term record. The median daily flow that month is about 11 cfs, against 6.2 cfs in January, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for Bear River below Drum Afterbay near Blue Canyon, CA?
- It depends on the month. In January, half of days historically fall near 6.2 cfs, with the middle 80% of days between 5.2 and 11 cfs. The month-by-month table on this page gives the full range.
- How long has Bear River below Drum Afterbay near Blue Canyon, CA been measured?
- Discharge records at USGS site 11421770 begin in 1966, about 60 years, covering roughly 6,789 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Where is Bear River below Drum Afterbay near Blue Canyon, CA?
- The gauge sits at 39.25434, -120.77494, in California, in hydrologic subbasin 18020126, draining roughly 12 square miles.
- Can I use Bear River below Drum Afterbay near Blue Canyon, 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.
Upstream and downstream on the Bear River
Every gauge Rivermatics tracks on this river, ordered by drainage area — upstream first. See the Bear River in full.
- Bear River near Emigrant Gap, CA 1 sq mi
- Bear River below Drum Afterbay near Blue Canyon, CA this page
- Bear River below Dutch Flat Afterbay near Dutch Flat, CA 22 sq mi
- Bear River below Rollins Dam near Colfax, CA 105 sq mi
- Bear River near Wheatland, CA 292 sq mi
Other gauges in this subbasin
- Chicago Park Flume near Dutch Flat, CA
- Bear River below Dutch Flat Afterbay near Dutch Flat, CA
- Bear River Canal Intake near Colfax, CA
- Bear River below Rollins Dam near Colfax, CA
- Bear River near Wheatland, CA
- Dry C near Wheatland, CA
- Bear River near Emigrant Gap, CA
- Dutch Flat No 2 Flume near Blue Canyon, CA