Marias River Near Shelby Mount
USGS Site No: 06099500 • Marias River • Toole County, MT
Marias River Near Shelby Mount on the Marias River is currently at 2,100 cfs (Very High — 109th percentile for this date) . Gage height: 5.11 ft.
Reading from
Historical Percentile Comparison
Today's discharge compared to the long-term record for October 28 at this station. Percentile rank shows what fraction of historical years had lower flow on this date.
| Percentile | Label | CFS Threshold | Today's Flow |
|---|---|---|---|
| 10th | Very Low threshold | 164 | |
| 25th | Low threshold | 221 | |
| 50th (Median) | Normal (median) | 308 | |
| 75th | High threshold | 452 | |
| 95th | Very High threshold | 871 |
30-Day Hydrograph
Recent discharge plotted against the historical 10th–95th percentile envelope for the same calendar days. Source: USGS daily values + long-term statistics.
30-Day Flow History
| Date | Discharge (CFS) | Gage Ht (ft) |
|---|---|---|
| May 28, 2026 | 1,810 | — |
| May 27, 2026 | 1,450 | — |
| May 26, 2026 | 1,140 | — |
| May 25, 2026 | 896 | — |
| May 24, 2026 | 822 | — |
| May 23, 2026 | 878 | — |
| May 22, 2026 | 963 | — |
| May 21, 2026 | 1,030 | — |
| May 20, 2026 | 1,150 | — |
| May 19, 2026 | 1,310 | — |
| May 18, 2026 | 1,510 | — |
| May 17, 2026 | 1,730 | — |
| May 16, 2026 | 2,050 | — |
| May 15, 2026 | 2,210 | — |
| Apr 20, 2026 | 778 | — |
| Apr 19, 2026 | 796 | — |
| Apr 18, 2026 | 834 | — |
| Apr 17, 2026 | 848 | — |
| Apr 16, 2026 | 833 | — |
| Apr 15, 2026 | 867 | — |
| Apr 14, 2026 | 858 | — |
| Apr 13, 2026 | 836 | — |
| Apr 12, 2026 | 751 | — |
| Apr 11, 2026 | 734 | — |
| Apr 10, 2026 | 743 | — |
| Apr 9, 2026 | 764 | — |
| Apr 8, 2026 | 774 | — |
| Apr 7, 2026 | 755 | — |
| Apr 6, 2026 | 786 | — |
| Apr 5, 2026 | 854 | — |
Station Information
- USGS Site No
- 06099500
- State
- MT
- County
- Toole County
- Coordinates
- 48.4272, -111.8898
- Drainage Area
- 2,716 mi²
- Datum (ft)
- 3,087.7
- HUC Code
- 10030203
Flood Stage Thresholds
- Action Stage
- 8.0 ft
- Flood Stage
- 9.0 ft
- Moderate Flood
- 13.0 ft
- Major Flood
- 15.0 ft
Currently 3.89 ft below flood stage.
Recent Extremes
- Max discharge
-
2,880 cfsMar 22, 2026
- Min discharge
-
83 cfsOct 1, 2025
- Days at flood stage
- 0
Computed from the local daily-values archive.
Nearby Gauges
-
Birch Creek at Bullhead Bridge, near Valier, MountNormal19.9 mi · 30 cfs
-
Willow Creek Near Galata, MountNormal25.0 mi · 0 cfs
-
Cut Bank Creek at Cut Bank MountVery High25.3 mi · 446 cfs
-
Birch Creek at Robare, MountNormal31.9 mi · 9 cfs
-
Two Medicine River above Badger Creek, near Piegan, MountVery High33.6 mi · 1,080 cfs