Flood in Sanders County, Montana

The DES coordinator for Sanders County reported that the Little Bitterroot River flooded with 2 to 3 feet of water observed in places. The Little Bitterroot Road from Anderson's Corner to Sloan's Bridge was closed for 4 days. According to a river gauge located at one of the river's headwaters, Mill Creek, the discharge rate peaked at 238 cubic feet per second at 3:15 pm MST on March 6. In 31 years, this value surpassed the previous record of 53 cubic feet per second set back in 1986. A local rancher reported that this was the worst flooding he had ever seen. In terms of damage, the Little Bitterroot Road experienced minor damage with several culverts that needed to be replaced while homes were spared. Observations were sparse in the region, but a COOP observer located 2 miles northwest of Heron reported a 48 hour precipitation total of 1.99 between March 9-10. The combination of above normal snowfall that fell across western Montana in February, warm day and night-time temperatures and the rainfall contributed to substantial snow-melt in this event.

A period of very warm temperatures ranging from 50 to 60 degrees occurred after an above normal snowfall winter across western Montana. This combined with moderate to heavy rainfall and high snow levels resulted in a quick melt of snowpack in various locations. Impacts felt included road closures due to avalanche danger, flooding of the Little Bitterroot River, rock slides across northwest Montana and lowland flooding across the Bitterroot Valley. President Obama declared a major disaster in the state of Montana which included Sanders, Lake and Ravalli Counties to help with the flood cleanup costs.