Union Pacific Railroad said it expects to reopen a pair of storm-damaged lines for partial service as soon as Jan. 24.

The California Coast Line and another segment northeast of Las Vegas are the last of five rail lines severely damaged by a storm earlier this month.

"Our people have been working under very difficult conditions," said Dick Davidson, UP chairman and chief executive, in a prepared statement. "To call their efforts heroic would be an understatement."

The railroad said an embargo on traffic into California and Southern Nevada remains in place.

"We have been working closely with our customers to assure that critical chemical, grain and coal shipments into the affected areas are being handled," Davidson said. The carrier continues to work off the backlog of trains delayed by the storm.

The Coast Line was closed when the storm, along with torrential rain and heavy surf along the line triggered washouts, coastal sinkholes and covered the track with mud over a 139-mile stretch that runs next to the Pacific Ocean between Guadalupe and Moorpark, Calif.

In Nevada, UP said 200 personnel are working around the clock to repair storm damage over an 80-mile stretch in a remote canyon south of Caliente, Nev. The narrow canyon channeled floodwaters that washed out track in numerous locations and damaged bridges and signals.

Caliente is about 130 miles northeast of Las Vegas, and an important freight line between Los Angeles (schedules) , Salt Lake City and the Midwest.