The crash happened around 7 p.m. on SR-530 at 59th Avenue, just west of Arlington, according to Trooper Mark Francis.
Francis said a car driven by 55-year-old Mary Giebel was traveling east in the westbound lanes of SR-530 when it struck the victim's car.
The victim, a 59-year-old Arlington woman, was rushed to the Colby Campus of Providence Hospital in Everett with life-threatening injuries including several compound fractures, Francis said. Giebel was taken to Cascade Hospital with broken bones.
Francis said Giebel will be held for DUI vehicular assault.