USGS Streamgage 06130500
Musselshell River at Mosby, MT
Musselshell River at Mosby, MT is USGS streamgage 06130500 in Montana, monitoring river discharge in hydrologic subbasin 10040205. It sits on the Musselshell River, alongside 6 other gauges Rivermatics tracks on the same river. It drains a watershed of about 7,784 square miles. Discharge records at this site go back to 1929. Typical flow runs near 114.9 cfs in July and 135.4 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.
View live conditions & forecast →
Gauge details
- State
- Montana
- Drainage area
- 7,784 sq mi
- Gauge elevation
- 2,500 ft
- Subbasin (HUC-8)
- 10040205
- Coordinates
- 46.99469, -107.88916
- USGS site number
- 06130500
- Records begin
- 1929-05-01 (97 years)
- Rivermatics forecast
- 14-day flow outlook
14-day flow forecast
Based on observations through for Musselshell River at Mosby, 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 |
|---|---|---|---|---|
| 39.1 | 47.9 | 58.6 | ||
| 29.7 | 42.1 | 60.6 | ||
| 23.1 | 37 | 59.8 | ||
| 18.3 | 32.7 | 58 | ||
| 15 | 29.8 | 56.7 | ||
| 12.4 | 27.4 | 54.8 | ||
| 10.9 | 26.6 | 56.5 | ||
| 9.3 | 26.3 | 61.3 | ||
| 7.7 | 25.5 | 65.5 | ||
| 6.1 | 23.2 | 62.4 | ||
| 5 | 21.6 | 60.5 | ||
| 4.1 | 20 | 57.9 | ||
| 3.8 | 20.1 | 60.4 | ||
| 2.9 | 17.9 | 56.8 |
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 96 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 | 0.9 | 50.4 | 200.7 | |
| February | 4.5 | 80.4 | 356.8 | |
| March | 29.2 | 165.5 | 948.4 | |
| April | 15.2 | 135.4 | 790.7 | |
| May | 5.1 | 203 | 1,543.9 | |
| June | 15.4 | 338.8 | 2,678 | |
| July | 0.4 | 114.9 | 986.5 | |
| August | 0 | 61.6 | 293.5 | |
| September | 0 | 64.4 | 263.3 | |
| October | 0 | 66.9 | 219.3 | |
| November | 0.1 | 66.9 | 208.9 | |
| December | 0.5 | 54.5 | 192 |
All values in cubic feet per second (cfs).
Common questions
- When does Musselshell River at Mosby, MT normally run highest?
- June, on the long-term record. The median daily flow that month is about 338.8 cfs, against 50.4 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 Musselshell River at Mosby, MT?
- It depends on the month. In January, half of days historically fall near 50.4 cfs, with the middle 80% of days between 0.9 and 200.7 cfs. The month-by-month table on this page gives the full range.
- How long has Musselshell River at Mosby, MT been measured?
- Discharge records at USGS site 06130500 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 Musselshell River at Mosby, 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 Musselshell River at Mosby, MT?
- The gauge sits at 46.99469, -107.88916, in Montana, in hydrologic subbasin 10040205, at an elevation of about 2,500 feet, draining roughly 7,784 square miles.
- Can I use Musselshell River at Mosby, 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 Musselshell River
Every gauge Rivermatics tracks on this river, ordered by drainage area — upstream first. See the Musselshell River in full.
- Musselshell River near Martinsdale, MT 537 sq mi
- Musselshell River at Harlowton, MT 1,108 sq mi
- Musselshell River ab Mud Creek near Shawmut, MT 1,518 sq mi
- Musselshell River ab Big Coulee Creek at Lavina, MT 2,691 sq mi
- Musselshell River near Roundup, MT 3,998 sq mi
- Musselshell River at Musselshell, MT 4,534 sq mi
- Musselshell River at Mosby, MT this page
Other gauges in this region
- N F Milk River ab St. Mary canal near Browning, MT
- Milk River at Eastern Crossing of Int Bndry
- Lodge Creek near Chinook, MT
- Battle Creek near Chinook, MT
- Rock Creek below Horse Creek near int'l boundary
- Yellowstone River at Billings, MT
- Bighorn River at Basin, WY
- North Fork Shoshone River at Wapiti, WY