Floods of January 15-17, 1974, in Northwestern Montana

Introduction

Rain and snowmelt caused several streams in northwestern Montana to flood during January 15-17, 1974. The flooding was caused by a major rainstorm that extended from Montana through Idaho and Washington. The most damage occurred in the Kootenai River drainage, centering around the town of Libby. Also unusually high flows occurred on some streams in the Clark Fork basin. Throughout the area, ice jams contributed to much of the overbank flooding.

Both the towns of Troy and Libby were partly flooded, but damage was greatest in and near Libby. Flood damage was estimated to be $4.9 million. No flood fatalities were listed. Most of the smaller streams equaled or exceeded a 50-year flood. A summary of flood stages and discharges for 24 sites in the Kootenai River drainage and 8 sites in the Clark Fork drainage is tabulated. A map shows the extent of flooding in the Libby area. (Woodard-USGS)