MINNEAPOLIS — The nation’s congested railways are having an effect on Minnesota’s taconite industry.

Iron ore pellets that are produced near mines in northern Minnesota and transported by train to the Twin Ports are getting backed up. Industry officials worry about delivering enough iron ore to steelmakers before the Great Lakes shipping season ends.

Sen. Amy Klobuchar said at a recent transportation committee hearing that one mining company has 250,000 tons of taconite piled up because of rail service delays. Another has 85,000 tons stockpiled.

A shortage of locomotives and train crews is blamed for the backups. Last winter’s weather also shortened the shipping season.