The incident happened at Bridle Trails State Park in Kirkland, police said.
Police said a grandmother was walking with her 2-year-old grandchild on a trail when an unknown woman hit the grandmother in the head from behind, grabbed the boy and ran away.
The child's mother was in a vehicle with her baby when she saw the unknown woman with her son, police said. The grandmother and the mother chased after the suspect.
Police said there was a scuffle and the mother and grandmother were able to get the child back and escape from the suspect.
A Kirkland police officer was on patrol and saw the mother standing in the parking lot with a woman who witnessed the incident.
The suspect reappeared from the wooded area and the officer took the suspect into custody.
The grandmother had some abrasions to her head and the mother and children were not hurt.
Lori Edgerton has five children and twice as many grandchildren, and the Kirkland mother said she would go after anyone who tried to hurt any one of them.
“Oh yeah, I’d be all over that, I would be chasing them down. I mean, I don’t think you cannot chase them down,” Edgerton said.
Police said the suspect told them she thought the child was in danger. She was booked into the King County jail on assault and attempted kidnapping
“That leaves you feeling like there’s nothing you can do -- even when you’re holding your child’s hand somebody can take your child,” Edgerton said.
The investigation is ongoing.