BILLINGS, Mont. — Flooding disrupted emergency phone service across a broad swath of eastern Montana on Monday as areas of the state remained inundated and downstream communities prepared for the worst.
Residents of one southeast South Dakota town were told to be ready to leave their homes by Thursday as the Missouri River continued to rise.
Authorities say northwestern Montana and the Dakotas are next in line for problems as mountain snow melts and record flows are released from the Missouri's swollen reservoirs.
"This could be a pretty significant week for flooding, and it might expand," said Monique Lay, spokeswoman for the Montana Emergency Coordination Center.
Residents of Dakota Dunes, S.D., were told on Memorial Day to prepare to leave their homes by Thursday as the Missouri River continued to rise. Gov. Dennis Daugaard stressed that no evacuation had been ordered, but the town's 2,500 people were told to prepare for the worst.
Eric Stasch, operations manager at Oahe Dam upstream in north-central South Dakota, said many levees being built in the Pierre-Fort Pierre area to protect public infrastructure also will shield private property. But he said residents in flood-threatened areas should not assume the levees will be done in time or hold against the record dam releases.
Another 200 South Dakota National Guard troops were called to help battle flooding along the river, bringing the total to more than 600. The Guard also has been called out in parts of Montana and Wyoming.
In the central Montana town of Roundup, houses and businesses remained under several feet of water from the Musselshell River, which first topped its banks and swept through town Thursday.
A mandatory boil-water order was issued, said Maj. Lori Hampa-Chamberlin of the Montana National Guard. Crews were working to pull stranded vehicles out of flooded areas and most routes into or out of the town were cut off.
Brian Tesar with the National Weather Service in Billings said the expected warm-up later in the week raised the chances of flooding along the Yellowstone, Tongue and Shields rivers in central and eastern Montana.