You can check the park web sites. US2 around the south side of Glacier will be open, but Going To The Sun through Glacier is a late opening. There's still stuff to see on the west side, along with tourist towns. East side access points are through the Blackfoot Reservation, and have been closed this year.
East of the mountains, US2 is open flat and straight, with a few small towns and a scattering of rec sites (COE). Camping in western ND used to hard to find due the oil field activity, but the past year may have cooled that.
There have been tons of Yellowstone questions.