Is the Big Lost River flooding?

Idaho · 9 gauges · Idaho river levels

The Big Lost River is tracked by 9 USGS streamgauges in Idaho. This page compares each gauge’s live water level against its official National Weather Service flood stage, refreshed every 15 minutes, so you can tell whether the Big Lost River is running normal, rising toward flood stage, or already flooding. 3 of 9 gauges have both a usable water-level reading and a published minor flood stage. Gauges without a published flood stage show water level and flow only. For nearby rivers, see all Idaho river levels.

data refreshed 14 min ago

Readings may be delayed; check each observation time below. This gauge summary does not rule out flooding on unmonitored stretches or nearby streets.

River facts

The longest-running gauge on this river is Big Lost River below Mackay Reservoir near Mackay ID. The highest level ever recorded there was 6.08 ft on 6 June 1986, carrying 2,990 cfs. Peak records there go back to 1904 (112 annual peaks). It is currently at 2.30 ft, 3.8 ft below that record.

Drains 801 sq mi · gauge elevation 5,951 ft · source: USGS peak-flow record

GaugeStatusStageFlood stageUpdated
Big Lost River at Howell Ranch near Chilly IDNo flooding0.98 ft4.05 ft
Big Lost River below Mackay Reservoir near Mackay IDNo flooding2.30 ft4.3 ft
Big Lost River near Arco IDNo flooding2.01 ft6.5 ft
Big Lost River below Inl Div near Arco IDNo current data
Big Lost River at Lincoln Blvd Bridge near Atomic CityNo current data14.75 ft
Big Lost River above Big Lost River Sinks near Howe IDNo current data
Big Lost River near Leslie IDNo flood stage defined5.38 ft
Big Lost River below Moore Div near Moore IDNo flood stage defined9.39 ft
Big Lost River at Arco at Sunset Road IDNo flood stage defined5.08 ft
Provisional data: Real-time readings are provisional and subject to revision by the USGS — sensors can be affected by ice, debris, or equipment malfunction. Do not rely on this site for decisions involving personal safety; follow official guidance from the National Weather Service and local authorities.