The boy, identified as Nathan Hernandez, reportedly was first spotted by a helicopter, and then a team with dogs located him at about 10 a.m. Friday, the King County Sheriff's Office reported. He was hungry and thirsty but otherwise appeared to be OK.
Rescuers gave him food and water. He was checked by medics and reunited with his family.
Hernandez went missing at about noon Thursday while picking berries and playing hide-and-seek with his sisters on property the family owns near Lake Cushman. The family searched for him until dark and then called for help at about 9 p.m.
The sheriff's office says searchers used dogs and heat-detecting technology in the overnight search. A helicopter joined the search at daybreak Friday.
A footprint was found in the mud Friday morning and searchers located the boy about two hours later.