roads that are throughways — like, how to get from one town to another — SHOULD be open. i lived in montana in 95 and that’s how it was. park entrances are closed, as are national forests and all other federally owned lands. so if it’s not a through road, it could be difficult. i’d check maps to see what you’re crossing (roads that cross over national forests should likely be open). other than that … i’m honestly not sure. i’d check with locals and be prepared to adjust your route accordingly.