Big Backyard 5K
June 7, 2026 @ 7:00 am - 11:00 am
Founded in 2010, the Big Backyard 5K, also known as the BBY5K, is a 5K run/walk at King County’s Marymoor Park. The event is family friendly and strollers and leashed dogs are always welcome on the course.
Proceeds from the BBY5K benefit King County Parks and brings the organization financial support for maintenance and operations of Your Big Backyard. With your help over the years, we have raised more than $250,000 for King County Parks!
Celebrating 10 years in 2019, we are adding a 10K distance option to commemorate this milestone year! Join us again and help us celebrate! Pick your distance and find your pace. Run/Walk 5K or Run 10K!
The event is family friendly and strollers and leashed dogs are always welcome on the course. Don’t forget to stick around after your run/walk for a FREE Kids Dash and post-race festivities featuring refreshing drinks, tasty food, great tunes, and fun prize giveaways.
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