USGS Streamgage 06020600
Ruby River below reservoir near Alder, MT
Ruby River below reservoir near Alder, MT is USGS streamgage 06020600 in Montana, monitoring river discharge in hydrologic subbasin 10020003. It sits on the Ruby River, alongside 2 other gauges Rivermatics tracks on the same river. It drains a watershed of about 595 square miles. Discharge records at this site go back to 1962. Typical flow runs near 319.9 cfs in July and 69.4 cfs in April, with the higher of the two arriving in July. 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
- 595 sq mi
- Gauge elevation
- 5,294 ft
- Subbasin (HUC-8)
- 10020003
- Coordinates
- 45.24187, -112.11124
- USGS site number
- 06020600
- Records begin
- 1962-11-30 (64 years)
- Rivermatics forecast
- 14-day flow outlook
14-day flow forecast
Based on observations through for Ruby River below reservoir near Alder, 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 |
|---|---|---|---|---|
| 251 | 258 | 265 | ||
| 246 | 257 | 266 | ||
| 240 | 257 | 267 | ||
| 226 | 255 | 269 | ||
| 213 | 254 | 270 | ||
| 199 | 253 | 272 | ||
| 181 | 250 | 272 | ||
| 175 | 247 | 272 | ||
| 170 | 245 | 271 | ||
| 163 | 241 | 271 | ||
| 158 | 239 | 271 | ||
| 145 | 234 | 270 | ||
| 142 | 232 | 270 | ||
| 138 | 229 | 269 |
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 63 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 | 25.6 | 43.9 | 83.1 | |
| February | 24.1 | 42.3 | 73 | |
| March | 25.2 | 44.7 | 106.8 | |
| April | 33.5 | 69.4 | 187.6 | |
| May | 184.9 | 375.2 | 700.7 | |
| June | 297.1 | 472.7 | 967.3 | |
| July | 245.1 | 319.9 | 474 | |
| August | 254.5 | 333.3 | 429.7 | |
| September | 145.4 | 238.8 | 335.9 | |
| October | 43.8 | 85.8 | 187.5 | |
| November | 36.8 | 61.6 | 109.8 | |
| December | 27.2 | 46.2 | 95.8 |
All values in cubic feet per second (cfs).
Common questions
- When does Ruby River below reservoir near Alder, MT normally run highest?
- June, on the long-term record. The median daily flow that month is about 472.7 cfs, against 42.3 cfs in February, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for Ruby River below reservoir near Alder, MT?
- It depends on the month. In January, half of days historically fall near 43.9 cfs, with the middle 80% of days between 25.6 and 83.1 cfs. The month-by-month table on this page gives the full range.
- How long has Ruby River below reservoir near Alder, MT been measured?
- Discharge records at USGS site 06020600 begin in 1962, about 64 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 Ruby River below reservoir near Alder, 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 Ruby River below reservoir near Alder, MT?
- The gauge sits at 45.24187, -112.11124, in Montana, in hydrologic subbasin 10020003, at an elevation of about 5,294 feet, draining roughly 595 square miles.
- Can I use Ruby River below reservoir near Alder, 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 Ruby River
Every gauge Rivermatics tracks on this river, ordered by drainage area — upstream first. See the Ruby River in full.
- Ruby River above reservoir near Alder, MT 534 sq mi
- Ruby River below reservoir near Alder, MT this page
- Ruby River near Twin Bridges, MT 970 sq mi