Flood — Dalton Highway Summits, Alaska

2025-08-26 · near Prospect Creek, Dalton Highway Summits, Alaska

Event narrative

Water over the Dalton Highway caused the road to wash out between mile markers 142 and 144 just north of Prospect Creek. The Alaska DOT was forced to completely close the roadway between mile markers 112 and 156. All traffic was stopped at the Jim River DOT Camp.

Wider weather episode

A prolonged period of deep moist southwesterly flow from the North Pacific ocean, otherwise known as an Atmospheric River, produced several days of heavy rainfall along the south slopes of the Brooks Range. Over about a 5 day period total rainfall of three to six inches resulted in considerable flooding for the Koyukuk and it's tributaries. In addition this southwest flow also resulted in very strong winds through the Alaska Range passes.

View location on OpenStreetMap → (66.5587, -150.9678)

Source: NOAA Storm Events Database, event_id 1293373. Narrative written by the NWS forecast office that issued the report.