Yellowtail Reservoir Water Level Today
Montana · near Billings · Below full pool
- Elevation
- 3,623.41 ft
- From full pool
- −16.59 ft
- Percent of pool
- 82.2%
- 24-hour change
- +0.11 ft
- 7-day change
- +0.37 ft
- Reading
- Sep 21, 2026 · USACE
Last year at Yellowtail Reservoir
Yellowtail Reservoir is 16.59 ft below full pool, at 3,623.41 ft, up 0.11 ft in the last 24 hours. That puts the lake at 82.2 percent of its conservation pool. The top of the flood pool is 33.6 ft higher, at 3,657.00 ft.
Over the last 7 days the level rose 0.37 ft, and over 30 days it rose 0.47 ft. In the 399 days of readings on this page the high was 3,633.29 ft on Oct 26, 2025 and the low was 3,613.76 ft on Apr 16, 2026, a range of 19.53 ft.
The reading is the U.S. Army Corps of Engineers gauge at Yellowtail Dam & Reservoir, near Billings, taken Sep 21, 2026 and referenced to the NGVD29 datum. This page is rebuilt once a day from the agency feed; it is not a live gauge, so during a fast rise or a scheduled release check the USACE page for hourly values.
Yellowtail Reservoir pool elevations
| Current elevation | 3,623.41 ft |
|---|---|
| Full pool (top of conservation) | 3,640.00 ft |
| Top of flood pool | 3,657.00 ft |
| Bottom of conservation pool | 3,547.00 ft |
| Top of dam | 3,660.00 ft |
| Inflow | 2,680 cfs |
| Outflow | 1,991 cfs |
| 30-day change | +0.47 ft |
| 1-year high | 3,633.29 ft (Oct 26, 2025) |
| 1-year low | 3,613.76 ft (Apr 16, 2026) |
| Vertical datum | NGVD29 |
| Operating agency | U.S. Army Corps of Engineers, NWO district |
Source: U.S. Army Corps of Engineers. Read what full pool and flood pool mean.
More lakes in Montana
- Fort Peck Lake 2,222.45 ft, −11.55 ft from full
- Lake Koocanusa 2,444.76 ft, −14.24 ft from full
- Canyon Ferry Reservoir 3,785.41 ft, −11.59 ft from full
- Clark Canyon Reservoir 5,514.74 ft, −31.36 ft from full
- Flathead Lake 2,893.05 ft, +0.05 ft from full
- Tiber Reservoir 2,988.17 ft, −4.83 ft from full
Yellowtail Reservoir level questions
What is the water level of Yellowtail Reservoir today?
Yellowtail Reservoir is at 3,623.41 ft as of Sep 21, 2026, −16.59 ft relative to full pool (3,640.00 ft). The 24-hour change is +0.11 ft.
What is full pool at Yellowtail Reservoir?
Full pool, the top of the conservation pool, is 3,640.00 ft (NGVD29). Above that, water is stored temporarily in the flood pool up to 3,657.00 ft. The bottom of the conservation pool is 3,547.00 ft.
Is Yellowtail Reservoir rising or falling?
Over the last 24 hours the level is +0.11 ft; over 7 days it rose 0.37 ft, and over 30 days it rose 0.47 ft.
Where does this Yellowtail Reservoir level come from?
From the U.S. Army Corps of Engineers (USACE) public data feed for Yellowtail Dam & Reservoir. Lake Levels Today republishes the agency's daily value without adjustment and links to the source below.