USGS Streamgage 12355500
N F Flathead River near Columbia Falls, MT
N F Flathead River near Columbia Falls, MT is USGS streamgage 12355500 in Montana, monitoring river discharge in hydrologic subbasin 17010206. It drains a watershed of about 1,556 square miles. Discharge records at this site go back to 1910. Typical flow runs near 3,538.4 cfs in July and 2,925.7 cfs in April, with the higher of the two arriving in July.
Gauge details
- State
- Montana
- Drainage area
- 1,556 sq mi
- Gauge elevation
- 3,150 ft
- Subbasin (HUC-8)
- 17010206
- Coordinates
- 48.4958, -114.12676
- USGS site number
- 12355500
- Records begin
- 1910-10-01 (116 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 86 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 | 413.3 | 659.6 | 1,213.5 | |
| February | 416.3 | 636.6 | 1,182.1 | |
| March | 491.1 | 772.8 | 1,667.1 | |
| April | 1,193.2 | 2,925.7 | 6,111.7 | |
| May | 4,995.8 | 8,908.4 | 15,812.9 | |
| June | 4,754 | 9,198 | 15,950 | |
| July | 1,760 | 3,538.4 | 6,445.5 | |
| August | 937.4 | 1,489 | 2,323.2 | |
| September | 700.8 | 994 | 1,630.7 | |
| October | 626 | 912 | 1,925.5 | |
| November | 603.7 | 938.2 | 2,245.7 | |
| December | 506.6 | 758 | 1,673.2 |
All values in cubic feet per second (cfs).