Pretty amazing coincidence...
Heading west from Portland, US 26 enters the path of totality near Mt. Hood, and remains within the path for about 330 miles, all the way to the Idaho border:
Then, after swinging south through Boise, US 26 re-enters the path of totality near Shelley ID, and remains within the path for an astounding 635 miles, almost all the way to its eastern terminus in Ogallala NE:
The moon's shadow will be exceeding the speed limit on US 26 by about 1600 mph.
(Graphics on this page courtesy of Michael Zeiler, www.GreatAmericanEclipse.com)