Bringing students back in any capacity will lead to new infections, the report found.
A spike in cases could cause hospitalizations and deaths to rise soon.
Officials urge the public to continue social distancing.
Boat ramps, trailheads and golf courses can reopen with social-distancing measures in place.
It was unclear when sites would re-open, but employees will have to have PPE and stay six feet apart.
State Superintendant Chris Reykdal said Wednesday the lowest grade a student can earn is an incomplete.
Swedish Health Services is going through its bank of recovered patients and asking them to donate.
The study, under peer review, was led by an Everett Clinic doctor. It could speed up testing nationwide.
The governor is orchestrating a four-day bargaining session with both sides led by an MIT professor.
