Join us for the 2026 Big Backyard 5K & 10K at Marymoor Park on Sunday, June 7. It is a fun, family-friendly run and walk for all ages and abilities.

King County employees can take advantage of a 50% registration discount by using the code KCP50. Register here. This discount code has not been previously mentioned.

All employees are eligible for the discount. If you registered and did not receive the discount, please reach out to Mirsa Rutledge at MiRutledge@kingcounty.gov for your discount refund.

This annual event is a great way to get outside for a run or walk with friends, family, and community in King County’s beautiful Marymoor Park while supporting King County Parks. Since the event’s inception in 2010, more than 15,000 participants have gathered to raise over $95,000 for King County Parks!”