USGS Streamgage 06038500
Madison River below Hebgen Lake near Grayling, MT
Madison River below Hebgen Lake near Grayling, MT is USGS streamgage 06038500 in Montana, monitoring river discharge in hydrologic subbasin 10020007. It drains a watershed of about 931 square miles. Discharge records at this site go back to 1938. Typical flow runs near 986.8 cfs in July and 841.8 cfs in April, with the higher of the two arriving in July.
Gauge details
- State
- Montana
- Drainage area
- 931 sq mi
- Gauge elevation
- 6,459 ft
- Subbasin (HUC-8)
- 10020007
- Coordinates
- 44.86639, -111.33878
- USGS site number
- 06038500
- Records begin
- 1938-10-01 (88 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 88 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 | 712 | 873.9 | 1,178.4 | |
| February | 650.4 | 824.6 | 1,113.4 | |
| March | 499.3 | 813.3 | 1,241.6 | |
| April | 353.6 | 841.8 | 1,584 | |
| May | 223 | 785 | 1,714.8 | |
| June | 297.8 | 1,098.9 | 2,360.7 | |
| July | 690.4 | 986.8 | 1,456.1 | |
| August | 798.9 | 1,025.5 | 1,348.4 | |
| September | 760 | 1,060.8 | 1,532 | |
| October | 693.4 | 1,064.4 | 1,986.8 | |
| November | 689.6 | 1,098.8 | 2,042 | |
| December | 705.1 | 888.9 | 1,257.4 |
All values in cubic feet per second (cfs).
Other gauges in this subbasin
- Madison River at Kirby Ranch near Cameron, MT
- Madison River near Cameron, MT
- Madison River at Ennis, MT
- Madison River ab powerplant near McAllister, MT
- Madison River below Ennis Lake near McAllister, MT
- Madison River near Norris, MT
- Firehole River at Old Faithful, YNP
- Firehole River near West Yellowstone, MT