All foreign registered and licensed motor vehicles, trailers, semitrailers, or pole trailers must carry in plain sight on the motor vehicle, trailer, semitrailer, or pole trailer the license plates or device from the other state or foreign country.
Mont. Code Ann. § 61-3-702
Foreign vehicles to display license plates
En
Official source: Montana Code Annotated (Montana Legislature). Reproduced from public-domain Montana statutes; confirm against the official source for the current text. Not legal advice.