A flood warning on the Gallatin River near Logan, Montana, earlier this week was related to ice formations on area rivers this winter.

Ice has been forming with the cold temperatures that have been common this season in Montana. The National Weather Service and the Montana Department of Transportation keep an eye on ice formation, especially upstream from bridges or major bends in the river.

As an example, the Bitterroot River has a conglomeration of ice just upstream of Hamilton's Veterans Bridge. You can see how the ice flows pile up as the water slows rounding the bend west of US 93.

There's no flooding here, but some pretty impressive slabs of ice.

In past years, flooding because of ice has occurred in the Bitterroot Valley, so be aware and report any flooding to authorities.

Officials say ice jams usually occur early in the winter or as we approach spring, when cold days and warm days go back and forth. The ice formation teams up with melting to create ice jams, sending water out of the banks above the jam, and when the jam breaks, a flash flood downstream.