Cody J. Eads, 19, entered the plea last Thursday in connection with the death of Lucinda Pieczatkowski, 57.
Pieczatkowski was killed at about 1:50 a.m. on Jan. 1 when she was hit by a pickup while walking alone in the darkness along Stone Quarry Road, also known as 394 Place SE, near Snoqualmie.
In pleading guilty, Eads admitted he was speeding and texting when he hit Pieczatkowski, who was walking on the side of the road.
According to court documents, Eads had been drinking at a New Year's Eve party at a friend's house when he got into an argument with his girlfriend and decided to leave. He left the party at about 1:30 a.m. and drove his F-150 Ford pickup towards his home on Stone Quarry Road.
At about the same time, Pieczatkowski was walking along the side of the road, wearing dark clothes, after getting into an argument with her boyfriend and leaving his vehicle.
She was struck and killed by Eads' pickup as she walked along the roadway, court documents say. Eads continued driving on without stopping, court papers say.
Eads will face a sentence range of 15 to 20 months in prison when he's sentenced in January.