USGS Streamgage 06033000
Boulder River near Boulder, MT
Boulder River near Boulder, MT is USGS streamgage 06033000 in Montana, monitoring river discharge in hydrologic subbasin 10020006. It drains a watershed of about 381 square miles. Discharge records at this site go back to 1929. Typical flow runs near 70.9 cfs in July and 129.8 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.
View live conditions & forecast →
Gauge details
- State
- Montana
- Drainage area
- 381 sq mi
- Gauge elevation
- 4,824 ft
- Subbasin (HUC-8)
- 10020006
- Coordinates
- 46.21103, -112.09165
- USGS site number
- 06033000
- Records begin
- 1929-05-01 (97 years)
- Rivermatics forecast
- 14-day flow outlook
14-day flow forecast
Based on observations through for Boulder River near Boulder, 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 |
|---|---|---|---|---|
| 17 | 18.5 | 20.3 | ||
| 15.9 | 18 | 20.7 | ||
| 15 | 17.3 | 20.2 | ||
| 14.2 | 16.7 | 19.8 | ||
| 13.6 | 16.2 | 19.5 | ||
| 13.4 | 16.2 | 20 | ||
| 13.1 | 16.1 | 20.1 | ||
| 12.6 | 15.8 | 19.9 | ||
| 12.2 | 15.3 | 19.5 | ||
| 11.6 | 14.8 | 19.2 | ||
| 11.3 | 14.5 | 18.7 | ||
| 11.3 | 14.8 | 19.6 | ||
| 10.9 | 14.5 | 19.5 | ||
| 10.6 | 14.2 | 19.3 |
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 97 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 | 15.8 | 27.7 | 40.5 | |
| February | 18.2 | 30.3 | 43.3 | |
| March | 26 | 40.6 | 88 | |
| April | 51.1 | 129.8 | 338.5 | |
| May | 186.9 | 407 | 904.4 | |
| June | 122.2 | 335.3 | 847.4 | |
| July | 21 | 70.9 | 208.4 | |
| August | 9 | 23.4 | 71.8 | |
| September | 9.5 | 22.5 | 57 | |
| October | 16.5 | 32.9 | 69.5 | |
| November | 19 | 34.3 | 59.3 | |
| December | 17.4 | 28.6 | 44.4 |
All values in cubic feet per second (cfs).
Common questions
- When does Boulder River near Boulder, MT normally run highest?
- May, on the long-term record. The median daily flow that month is about 407 cfs, against 22.5 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 Boulder River near Boulder, MT?
- It depends on the month. In January, half of days historically fall near 27.7 cfs, with the middle 80% of days between 15.8 and 40.5 cfs. The month-by-month table on this page gives the full range.
- How long has Boulder River near Boulder, MT been measured?
- Discharge records at USGS site 06033000 begin in 1929, about 97 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 Boulder River near Boulder, 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. 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 Boulder River near Boulder, MT?
- The gauge sits at 46.21103, -112.09165, in Montana, in hydrologic subbasin 10020006, at an elevation of about 4,824 feet, draining roughly 381 square miles.
- Can I use Boulder River near Boulder, 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.