Around here
Around Big Lost River
- Appendicitis Hill Wilderness Study AreaRecreation area6.6 mi (opens in a new tab)
- White Knob Mountains Wilderness Study AreaRecreation area12.2 mi (opens in a new tab)
- Hawley Mountain Wilderness Study AreaRecreation area22.3 mi (opens in a new tab)
- Craters of the Moon National MonumentRecreation area23.4 mi (opens in a new tab)
Data Source: Recreation.gov · Public land: USGS PAD-US
About this river
Big Lost River is a 46.1 mile river. Streamflow is measured at the USGS gauge Big Lost River near Leslie ID (site 13130300). The National Hydrography Dataset places it at stream order 6. Reach geometry comes from the USGS National Hydrography Dataset.
Typical flow by month
2022 to 2026
Big Lost River typically runs highest in June, at a median 425 cfs, and lowest in November, at 48 cfs. The highest flow on record for any single day is 1,580 cfs, in 2023.
Show the numbers
| Month | Typical (cfs) | Usual range (cfs) |
|---|---|---|
| January | 52 | 38 to 65 |
| February | 64 | 48 to 72 |
| March | 72 | 51 to 84 |
| April | 74 | 54 to 227 |
| May | 329 | 227 to 447 |
| June | 425 | 325 to 893 |
| July | 358 | 303 to 563 |
| August | 242 | 161 to 405 |
| September | 197 | 134 to 250 |
| October | 144 | 71 to 182 |
| November | 48 | 33 to 163 |
| December | 52 | 32 to 62 |
Typical is the median of each month’s daily median values, and the usual range runs from the median 25th to the median 75th percentile, across about 4 years of record. Statistics published by the US Geological Survey for Big Lost River near Leslie ID (site 13130300). Conditions on any given day can fall well outside the usual range. Check the current reading before you go.
Boat access nearby
3 mapped launches sit in the mapped area of Big Lost River, all of them public access. Ramp data comes from the USGS national boat-ramp inventory.
- Mackay Reservoir - LowerMackay ReservoirPublic
- Mackay Reservoir - MiddleMackay ReservoirPublic
- Mackay Reservoir - UpperMackay ReservoirPublic
Made to print
Put Big Lost River on your wall
This river section as an art print, drawn over the real terrain with its miles, plus the trails, roads and peaks around it. Pick the colors and the size, and see the finished print before you buy. From $39, shipping included.
Embed this gauge on your site
Paste this snippet anywhere, an outfitter page, a club site, a trip report, to show Big Lost River's live streamflow, water level and 7-day trend. It reads the USGS gauge directly, updates itself, and links back here.
See every free widget you can put on your site, including live conditions and a 7 day forecast.
