USGS Streamgage 06306300
Tongue River at State Line near Decker, MT
Tongue River at State Line near Decker, MT is USGS streamgage 06306300 in Montana, monitoring river discharge in hydrologic subbasin 10090101. It drains a watershed of about 1,453 square miles. Discharge records at this site go back to 1960. Typical flow runs near 353.1 cfs in July and 303.6 cfs in April, with the higher of the two arriving in July.
Gauge details
- State
- Montana
- Drainage area
- 1,453 sq mi
- Gauge elevation
- 3,439 ft
- Subbasin (HUC-8)
- 10090101
- Coordinates
- 45.00914, -106.83594
- USGS site number
- 06306300
- Records begin
- 1960-07-08 (66 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 66 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 | 102.5 | 160 | 248.5 | |
| February | 110 | 187 | 341.1 | |
| March | 143.8 | 241.3 | 496.3 | |
| April | 180.2 | 303.6 | 602.7 | |
| May | 412.1 | 985.2 | 2,143.2 | |
| June | 389.5 | 1,475.4 | 3,184.7 | |
| July | 101.1 | 353.1 | 956.2 | |
| August | 61.4 | 141.2 | 313.8 | |
| September | 94.5 | 180.9 | 355.5 | |
| October | 153.2 | 237.4 | 346.7 | |
| November | 143.1 | 207 | 292.4 | |
| December | 106.8 | 166.7 | 242.6 |
All values in cubic feet per second (cfs).