Big Lost River below Mackay Reservoir near Mackay ID

USGS Site No: 13127000Big Lost River • Custer County, ID

Big Lost River below Mackay Reservoir near Mackay ID on the Big Lost River is currently at 710 cfs (Normal — 39th percentile for this date) . Gage height: 3.12 ft.

Reading from

710
CFS Discharge
3.12
Gage Height (ft)
Normal
Flow Condition
Normal
Flood Status

Historical Percentile Comparison

Today's discharge compared to the long-term record for June 11 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 389
25th Low threshold 550
50th (Median) Normal (median) 845 Today: 710 cfs
75th High threshold 1,240
95th Very High threshold 2,150

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.

1.8k 902 0 cfs Apr 5 May 28
10th–95th historical Day-of-year median Recent discharge

30-Day Flow History

Date Discharge (CFS) Gage Ht (ft)
May 28, 2026 669
May 27, 2026 623
May 26, 2026 529
May 25, 2026 433
May 24, 2026 427
May 23, 2026 428
May 22, 2026 449
May 21, 2026 489
May 20, 2026 512
May 19, 2026 557
May 18, 2026 582
May 17, 2026 631
May 16, 2026 724
May 15, 2026 648
Apr 20, 2026 87
Apr 19, 2026 86
Apr 18, 2026 85
Apr 17, 2026 84
Apr 16, 2026 83
Apr 15, 2026 83
Apr 14, 2026 82
Apr 13, 2026 81
Apr 12, 2026 80
Apr 11, 2026 79
Apr 10, 2026 78
Apr 9, 2026 77
Apr 8, 2026 77
Apr 7, 2026 76
Apr 6, 2026 75
Apr 5, 2026 75

Station Information

USGS Site No
13127000
State
ID
County
Custer County
Coordinates
43.9392, -113.6483
Drainage Area
801 mi²
Datum (ft)
5,950.6
HUC Code
17040218
View on USGS NWIS →

Flood Stage Thresholds

Action Stage
3.8 ft
Flood Stage
4.3 ft

Currently 1.18 ft below flood stage.

Recent Extremes

Max discharge
770 cfs
Jun 1, 2025
Min discharge
46 cfs
Nov 25, 2025
Days at flood stage
0

Computed from the local daily-values archive.

Nearby Gauges