Exit 121

I-15 South/I-90 West at Exit 121 - I-15 South/Dillon/Idaho Falls. Continue west on I-90 for Missoula.

I-15 North at I-15/I-90 Junction To Butte and Missoula, Silver Bow County

I-15 South/I-90 West approaching Exit 121. Use Exit 121 (I-15 South) for Dillon and Port of Montana Transportation Hub.

I-15 South/I-90 West Split at Exit 121. Merge right for I-15 south; continue straight for I-90 west.

I-15 north at Exit 121 - I-90 West/Missoula. Use right lanes to continue on I-15 North/I-90 East/Butte.

I-15 north approaching Exit 121 - I-90 West/Missoula and I-15 North/I-90 East/Butte. I-90 East joins I-15 northbound through Butte.