Photo property of Seattle Times
A section of highway 410 about 12 miles west of Naches on the east side of the Cascade Mountain, northwest of Yakima was blocked by a landslide this weekend, see Seattle Times story. This is the highway to and over Chinook Pass to the junction of highways 123, south from the Ohanopecosh entrance, and 410, north from the White River entrance and NP boundary.
This doesn't effect any of the NP entrances or the highway from Seatle, Tacoma or Portland, only the access east from Yakima and the Tri-cities area. The highway closes seasonally for winter snow, so it's likely this road will remain closed from the slide to the pass until late spring when it can be repaired and the pass is open. They're working on a temporary highway for local traffic.
This only changes the plans of any travellers and visitors who wanted the scenic route from the eastern side of the Cascade Mountains, who will have to take highway 12 to White Pass, and the junction of highway 12 southwest to Interstate 5 and Portland and highway 123 north to the Ohanopecosh entrance. White Pass also closes seasonally for snow and the Ohanopecosh entrance will close in October-November ahead of the annual snow.