9:35 a.m. Update
The crash scene has been cleared but motorists are asked to watch for people in the area investigating.
Traffic was slowed Wednesday morning on Interstate 90 near Hardin due to a rollover crash.
The Montana Department of Transportation reported at 8:20 a.m. the crash was blocking one lane of traffic between mile markers 498 and 499, about two miles east of Hardin.
A helicopter was expected to land at the scene and motorists should be prepared for a short delay.
The Montana Highway Patrol reports on its website the crash in the westbound lanes involves injury and was reported just after 8 a.m.
This is a developing story. Check back for updates.