USGS Streamgage 12340000
Blackfoot River near Bonner, MT
Blackfoot River near Bonner, MT is USGS streamgage 12340000 in Montana, monitoring river discharge in hydrologic subbasin 17010203. It sits on the Blackfoot River, alongside 1 other gauge Rivermatics tracks on the same river. It drains a watershed of about 2,287 square miles. Discharge records at this site go back to 1898. Typical flow runs near 1,561.1 cfs in July and 1,814.4 cfs in April, with the higher of the two arriving in April. Rivermatics issues a daily machine-learned flow outlook for this gauge, reaching 14 days ahead, alongside daily high and low water-temperature forecasts.
View live conditions & forecast →
Gauge details
- State
- Montana
- Drainage area
- 2,287 sq mi
- Gauge elevation
- 3,348 ft
- Subbasin (HUC-8)
- 17010203
- Coordinates
- 46.89941, -113.75632
- USGS site number
- 12340000
- Records begin
- 1898-07-01 (128 years)
- Rivermatics forecast
- 14-day flow outlook + water temperature
14-day flow forecast
Based on observations through for Blackfoot River near Bonner, MT. Each day carries a median estimate and the band the model expects the flow to fall within — not a single number to plan against. Forecasts are re-issued daily; see the live screen for the current outlook.
| Date | Low p10 | Expected p50 | High p90 | Range |
|---|---|---|---|---|
| 717 | 749 | 781 | ||
| 693 | 733 | 780 | ||
| 681 | 727 | 788 | ||
| 668 | 717 | 779 | ||
| 655 | 705 | 767 | ||
| 639 | 690 | 750 | ||
| 625 | 677 | 737 | ||
| 612 | 665 | 724 | ||
| 599 | 654 | 712 | ||
| 588 | 644 | 705 | ||
| 584 | 642 | 709 | ||
| 579 | 638 | 706 | ||
| 572 | 634 | 703 | ||
| 559 | 623 | 692 |
All values in cubic feet per second (cfs). Estimates only — do not use them for navigation or for any safety, rescue, or emergency decision.
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 128 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 | 356.6 | 521.5 | 772.5 | |
| February | 395.3 | 539.5 | 826.8 | |
| March | 466.2 | 697.5 | 1,328.5 | |
| April | 818.6 | 1,814.4 | 3,859.3 | |
| May | 2,269 | 4,590.3 | 8,526.8 | |
| June | 1,934.7 | 4,207.3 | 8,570.3 | |
| July | 765.7 | 1,561.1 | 2,942.9 | |
| August | 470.9 | 772.6 | 1,130.2 | |
| September | 415.5 | 636.3 | 883 | |
| October | 434.5 | 607.9 | 872.3 | |
| November | 458.5 | 607.8 | 907.2 | |
| December | 392.2 | 544.5 | 832.1 |
All values in cubic feet per second (cfs).
Common questions
- When does Blackfoot River near Bonner, MT normally run highest?
- May, on the long-term record. The median daily flow that month is about 4,590.3 cfs, against 521.5 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 Blackfoot River near Bonner, MT?
- It depends on the month. In January, half of days historically fall near 521.5 cfs, with the middle 80% of days between 356.6 and 772.5 cfs. The month-by-month table on this page gives the full range.
- How long has Blackfoot River near Bonner, MT been measured?
- Discharge records at USGS site 12340000 begin in 1898, about 128 years, covering roughly 9,200 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Is there a flow forecast for Blackfoot River near Bonner, MT?
- Yes. Rivermatics trains a machine-learned model — a temporal-fusion transformer — on this basin's observed flows, weather, and snowpack, and issues a daily flow outlook reaching 14 days ahead: a median estimate inside a confidence band, not a single number to bet on. A companion model forecasts each day's water-temperature high and low. Every forecast is scored against days the model never trained on, and that track record is published on the live gauge screen. Open live conditions to see the current outlook.
- Where is Blackfoot River near Bonner, MT?
- The gauge sits at 46.89941, -113.75632, in Montana, in hydrologic subbasin 17010203, at an elevation of about 3,348 feet, draining roughly 2,287 square miles.
- Can I use Blackfoot River near Bonner, MT 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 Blackfoot River
Every gauge Rivermatics tracks on this river, ordered by drainage area — upstream first. See the Blackfoot River in full.
- Blackfoot River ab Nevada Creek near Helmville, MT 498 sq mi
- Blackfoot River near Bonner, MT this page