Victims jumped off the Yellowstone River Bridge during the accident to avoid being hit by one of the cars, the Montana Highway Patrol (MHP) tweeted. They are expected to recover.
Authorities believe the cause of the accident was ice on the bridge, according to MHP.
The accident occurred on I-90 west, near the I-94 division in Lockwood, about six miles northeast of Billings. I-90 WB is shut down from that division while soldiers investigate the accident, MHP tweeted.
A special meteorological statement was issued by the National Weather Service in Billings early on Saturday afternoon, reporting that a strong blizzard has been observed moving into the area at 15 mph. The statement warned that the affected roads included I-94 and I-90 and that conditions could deteriorate rapidly.
The NWS has reported light snow and fog in the Billings area since Saturday morning, with temperatures around 20 degrees Fahrenheit in the morning and a maximum temperature of 32 degrees.