An ice jam 90 miles upriver from Bethel continues to threaten communities along the lower Kuskokwim River, prompting a flood warning through the evening of May 7.

The jam formed near Kalskag following breakup in Bethel on May 5. Water overflowed the road connecting Lower and Upper Kalskag, forcing early school release on May 5 and requiring some children to travel by boat. By May 6, water levels had dropped about half a foot, but sections of the road remained cut off.

The National Weather Service issued the flood warning for the Kuskokwim River at Kalskag. Affected communities include Kalskag, Bethel, Kwethluk, Napaskiak, Oscarville, and Akiak.

Downriver from the jam, open water now extends nearly bank to bank between Oscarville and Napaskiak. Ice continues to deteriorate toward the Johnson River. Residents near Akiak posted photos and videos showing massive ice movement on May 5.

U.S. Geological Survey gauges at Brown's Slough near Bethel recorded rapid stage rises that align with the timing of ice movement reported by residents and documented in social media posts.

The lower Kuskokwim has seen similar ice jams cause flooding and erosion in past years. In 2012, an ice jam near Akiak eroded 100 feet of riverbank in a single day, according to USDA Climate Hubs.

Small drops in river levels do not necessarily signal the end of flooding risk, according to the National Weather Service and historical data. Ice jams can re-form quickly during breakup, making outcomes difficult to predict.

The open water downriver from Bethel suggests the jam may eventually push downstream, which could ease pressure on upriver communities. However, the timing and extent of any such movement remains uncertain.

Kalskag sits at a point where the Kuskokwim River narrows, making it a common location for ice jams during spring breakup. The village has experienced flooding from similar jams in previous years.

Residents in affected communities continue to monitor river conditions closely. The flood warning remains in effect until the evening of May 7, though conditions could change as ice continues to move.

The National Weather Service continues to monitor conditions and will update the flood warning as the situation develops.