The crash happened about 9:45 a.m., Washington State Patrol trooper Mark Francis said.
Traffic had slowed in the area after a vehicle crashed into a guard rail and came to rest facing the wrong way on the freeway.
A Bellingham woman on a Honda touring bike rear-ended a Volkswagen Touareg SUV that had slowed down for the spinout, Francis said.
The motorcyclist, 24, was ejected onto the top of the SUV. She landed in the middle of the freeway. The Honda VT750 caught fire.
Paramedics tried to save the woman. She died at the scene.
Troopers are investigating whether speed was a factor in the crash.
The Volkswagen driver, a 48-year-old Issaquah woman, was taken to a local hospital for minor injuries. A dog in her SUV was not hurt.
Traffic was backed up for miles while detectives investigated the accident.
Troopers encourage drivers and motorcyclists to use caution as they share the roads.
"We need a collective effort to watch out for each other," trooper Keith Leary said.
More Local News Headlines
Water quality rules might be up to feds after Inslee drops rewrite 12s were counting on Russell Wilson signing contract Woman held as police investigate allegedly stolen mail Advisory group takes on Edmonds traffic Police nab alleged car prowler in Lynnwood Tulalip students help Seattle build tiny houses Everett couple’s hand-knit goods go to the homeless Faith Calendar
Our new comment system is not supported in IE 7. Please upgrade your browser here.