USGS Streamgage 10039500
Bear River at Border, WY
Bear River at Border, WY is USGS streamgage 10039500 in Idaho, monitoring river discharge in hydrologic subbasin 16010102. It drains a watershed of about 2,480 square miles. Discharge records at this site go back to 1937. Typical flow runs near 380.4 cfs in July and 457.3 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- Idaho
- Drainage area
- 2,480 sq mi
- Gauge elevation
- 6,057 ft
- Subbasin (HUC-8)
- 16010102
- Coordinates
- 42.21104, -111.0538
- USGS site number
- 10039500
- Records begin
- 1937-10-01 (89 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 89 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 | 97.8 | 148.3 | 270.2 | |
| February | 99.8 | 163.4 | 320.2 | |
| March | 130.4 | 261.5 | 656.8 | |
| April | 145.5 | 457.3 | 1,575.3 | |
| May | 190.5 | 724.6 | 2,092.9 | |
| June | 219 | 851.1 | 2,357.7 | |
| July | 132.4 | 380.4 | 1,094.9 | |
| August | 79.3 | 165 | 443.3 | |
| September | 68.9 | 127 | 311.6 | |
| October | 84.6 | 161.1 | 318.9 | |
| November | 118.6 | 179.6 | 310.4 | |
| December | 106.9 | 161.2 | 294 |
All values in cubic feet per second (cfs).
Common questions
- When does Bear River at Border, WY normally run highest?
- June, on the long-term record. The median daily flow that month is about 851.1 cfs, against 127 cfs in September, 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 at Border, WY?
- It depends on the month. In January, half of days historically fall near 148.3 cfs, with the middle 80% of days between 97.8 and 270.2 cfs. The month-by-month table on this page gives the full range.
- How long has Bear River at Border, WY been measured?
- Discharge records at USGS site 10039500 begin in 1937, about 89 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 Bear River at Border, WY?
- The gauge sits at 42.21104, -111.0538, in Idaho, in hydrologic subbasin 16010102, at an elevation of about 6,057 feet, draining roughly 2,480 square miles.
- Can I use Bear River at Border, WY 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.