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Hydrology Metering

Hungry Horse Dam · South Fork Flathead River · MT

Hungry Horse Reservoir

The Columbia system's cold-water bank in Montana — another reservoir where the USGS gage and Reclamation's record cross-check each other.

Water surface elevation

3,549.6 ft

USGS gage, 15-minute · Sep 2, 5:45 AM MDT

Water in storage

3.23 million acre-feet

Bureau of Reclamation, daily · daily value, Sep 1

Share of capacity

93.1% full

against the project figure capacity figure (USBR Hungry Horse project data)

Below full pool

10.4 ft

full pool at 3,560.0 ft

This month in the record

lower than 53% of the 74 Septembers on record

monthly mean storage; record low 1.03 million acre-feet (1952), record high 3.49 million acre-feet (1959)

30-day trend

-4,909 af/day

storage, 2026-07-312026-08-30; over the year -148 af/day. Measured change, not a forecast.

Drought at the dam

D0 — Abnormally dry

US Drought Monitor at the dam's coordinates, released 2026-08-27; the feeding basin can differ.

full pool 3,560 ftcolumn continues below3,550

93.1% full

of capacity, by storage (project figure figure, USBR Hungry Horse project data). Sedimentation slowly shrinks real capacity.

The water line is elevation (USBR project datum); the percentage is storage ÷ capacity. They are different measures — a reservoir's volume is not linear in its depth, so the line's height in this column is not the percentage.

Snowpack in the feeding basin

Measured across the Flathead headwaters.

Snow season

typically Oct 20 – Jun 18

0 in on the ground, 2026-09-01; median peak 25.2 in around Apr 24

Last winter's verdict

104% of median peak

water year 2026 — the snow that fed this year's pool

5 highest active SNOTEL stations in the basin (Barker Lakes, Saddle Mtn., Warm Springs, …), NRCS AWDB REST (SNOTEL), station set pinned 2026-08-31. Daily snow-water equivalent against the stations' own 30-year medians; off season the percent is withheld rather than divided by zero.

The last 119 days

Daily water-surface elevation in feet. The axis hugs the data — it does not start at zero. Source: USGS NWIS daily values.

3542.63552.23561.7May 5Jul 3Aug 313549.8
See the numbers as a table
DateElevation (ft)
Aug 313549.85
Aug 303550.06
Aug 293550.28
Aug 283550.47
Aug 273550.70
Aug 263550.83
Aug 253551.12
Aug 243551.33
Aug 233551.51
Aug 223551.72
Aug 213551.92
Aug 203552.11
Aug 193552.33
Aug 183552.56
Aug 173552.80
Aug 163553.00
Aug 153553.21
Aug 143553.41
Aug 133553.57
Aug 123553.81
Aug 113554.05
Aug 103554.30
Aug 93554.51
Aug 83554.74
Aug 73554.95
Aug 63555.17
Aug 53555.38
Aug 43555.58
Aug 33555.80
Aug 23555.99

Most recent 30 days shown.

The whole record

Monthly mean elevation, Oct 1951 to Aug 2026. The axis spans the pools, not zero; elevations in USBR project datum. Months with fewer than 15 gaged days are dropped, and gaps in the record break the line. Source: USBR RISE, retrieved 2026-08-31.

monthly mean elevationpool reference lines
3,1883,3853,582Oct 1951Mar 1989Aug 2026full pool3,553
See the numbers as a table
MonthMean elevation (ft)Days gaged
Aug 20263553.130
Jul 20263558.431
Jun 20263558.129
May 20263548.830
Apr 20263545.330
Mar 20263541.231
Feb 20263539.328
Jan 20263545.631
Dec 20253547.331
Nov 20253541.330
Oct 20253543.831
Sep 20253549.630
Aug 20253554.531
Jul 20253557.831
Jun 20253553.130
May 20253534.931
Apr 20253519.730
Mar 20253510.531
Feb 20253514.628
Jan 20253521.931
Dec 20243527.731
Nov 20243532.830
Oct 20243538.531
Sep 20243545.330

Most recent 24 months shown; the full monthly series is in the page's API response.

Storage against capacity

Monthly mean storage in acre-feet, zero baseline. The dashed line is the project figure capacity figure (USBR Hungry Horse project data) — sedimentation slowly shrinks real capacity. Storage can legitimately rise past a conservation-pool line when the flood pool is in use.

monthly mean storagecapacity
01.8M3.7MOct 1951Mar 1989Aug 2026capacity3.3M
See the numbers as a table
MonthMean storage (acre-feet)Days gaged
Aug 20263,306,40330
Jul 20263,428,99531
Jun 20263,421,97829
May 20263,207,38330
Apr 20263,128,36030
Mar 20263,038,28531
Feb 20262,996,83928
Jan 20263,136,85231
Dec 20253,173,53931
Nov 20253,039,73130
Oct 20253,095,92831
Sep 20253,224,43030
Aug 20253,337,44931
Jul 20253,414,76131
Jun 20253,306,77330
May 20252,903,85631
Apr 20252,592,20030
Mar 20252,416,37331
Feb 20252,493,46328
Jan 20252,636,39131
Dec 20242,753,98431
Nov 20242,859,13130
Oct 20242,980,97631
Sep 20243,129,68230

Most recent 24 months shown.

Where these numbers come from

Readings at Hungry Horse Reservoir are the measuring agencies' own: each value above names its source (USGS gage, Bureau of Reclamation daily record, Army Corps project data, or this desk's committed copy) and its observation time in the reservoir's own time zone. The capacity figure is the project figure USBR Hungry Horse project data number; sedimentation slowly shrinks real capacity, so the vintage travels with the percent.