The June 2022 Yellowstone Floods: Rain on Deep Snow, and Record Rivers

On June 13–15, 2022, extraordinary floods poured down the Yellowstone River and its tributaries in northwestern Wyoming and south-central Montana. Yellowstone National Park, the Stillwater Mine and the towns of Belfry, Fromberg, Livingston and Red Lodge were evacuated; campers along the Stillwater River were rescued by boat. Roads and bridges were destroyed — including the main road to the park's north entrance from Gardiner — and homes, buildings and vehicles were swept away.

Washout on State Highway 419 along the Stillwater River, south of Nye, Montana, June 21, 2022. Photo by Seth Siefken, U.S. Geological Survey

How it happened

Record floods

The U.S. Geological Survey (USGS) kept its streamgages reporting through the flood — measuring flows and repairing damaged equipment — then surveyed high-water marks, calculated peaks where gages had been unreachable, and updated flood-frequency estimates.

• 17 streamgages in the upper basin recorded their highest flows ever, most with record river levels too.
• At 18 gages, the peak was bigger than a "1-percent" flood — one with a 1% chance of being exceeded in a given year — and at 9, bigger than a 0.2-percent flood.

Figure 1. Selected streamgages and a snow telemetry station in the Upper Yellowstone River Basin. Image from the U.S. Geological Survey

A warning downstream

The sharp rise at gages on the Lamar River and at Corwin Springs, just north of the park, gave Livingston and Billings warning. The crest took about 7 hours to travel the roughly 50 miles from Corwin Springs to Livingston, and about 35 hours to cover the 140 miles on to Billings, arriving on the morning of June 15.

Figure 2. Streamflow on the Lamar and Yellowstone rivers, June 11–18, 2022. Image from the U.S. Geological Survey

Surveying a high-water mark (a debris line) along Rock Creek in Red Lodge, June 29, 2022. Photo by Seth Siefken, U.S. Geological Survey

USGS and Montana Department of Natural Resources and Conservation crews mapped high-water marks along Rock Creek in Red Lodge, the Clarks Fork at Fromberg, and the Yellowstone from Tom Miner Creek to Laurel, funded by the Federal Emergency Management Agency and the state; the data are on the USGS Flood Event Viewer.

An old story on this river

Written records of big Yellowstone floods reach back to 1873, with a major one in 1881.

• 1894: one of the largest — "twenty inches above the high-water mark of last year," a local paper reported.
• 1918: 24 years later, an even worse flood: at Billings the water topped the old high-water mark by 19 inches; trains overturned, bridges washed out, travel stopped across southern Montana, and water ran 3–4 feet deep over the river approaches at Columbus. It was the largest well-recorded flood before 2022.
• 1978, 1996, 1997, 2011: more big floods. The 1978, 1996 and 1997 floods submerged sites such as Pompey's Pillar; 1978 caused more than $33 million in damage, with 19 counties in Montana and Wyoming declared disaster areas.

Are floods getting bigger?

The 2022 floods were rare by the standard of the past century. But USGS studies have found that annual peak streamflows have increased, over one or more of the periods studied, at most of the basin's streamgages analyzed.

Measuring the Yellowstone River near Livingston, June 14, 2022. Photo by Dan Armstrong, U.S. Geological Survey

The data are available through the USGS National Water Information System, StreamStats and the Flood Event Viewer.

Sources

Based on Katherine Chase, DeAnn Dutton, William Hamilton, Seth Siefken, Cassidy Vander Voort and Aroscott Whiteman, "June 2022 floods in the Upper Yellowstone River Basin," U.S. Geological Survey Fact Sheet 2024–3035, U.S. Geological Survey; a work of the United States government in the public domain. The 1894 quotation is from The Stillwater Bulletin.