Interstate 90 near Crow Agency and Hardin has reopened with single-lane traffic in both directions through the flooded area, the Montana Department of Transportation said late Tuesday morning.
About 1-to-2 inches of water remains on a section of the highway for several hundred feet, the agency said, and motorists are advised to use reduced speeds and caution when entering the water.
Cones and signs are in place to assist.
I-90 was closed between Hardin and the Wyoming state line Saturday as floodwaters spilling from the Little Bighorn River covered portions of the highway.
Montana Department of Transportation resources: