Get our free mobile app According to the Montana Highway Patrol Twitter post, they suspect ice on the Yellowstone River bridge may have been the cause for the pileup that shut down I-90 westbound at the I-94 interchange near Johnson Lane. The last two vehicles were being removed from the scene on I-90 at 2:13pm, according to MHP, but as of this story, that portion of I-90 westbound at I-94 remains closed. This story will be updated as more information becomes available. See the Must-Drive Roads in Every State