Big Backyard 10K
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Event Overview
The Big Backyard 5K/10K is an annual event with a 10K Run/Walk, a 5K Run/Walk, and a 1K Kids Run. It takes place at Marymoor Park in Redmond, Washington. The event celebrates King County Parks, with proceeds supporting park maintenance and recreational resources.
Event Details
The event was founded in 2010. Since then, it has had more than 13,000 participants and has raised over $80,000 for King County Parks.
Registration prices increase on specific dates. For the 10K, the price is $33 until April 3, 2026, rising to $50 on race weekend. For the 5K, it is $28 until April 3, rising to $45. The 1K Kids Run is $15 until June 6, 2026.
Course Information
Both the 10K and 5K courses start and finish at the Marymoor Park Recreation and Event Area. They use the Marymoor Connector Trail and the Sammamish River Trail. The event takes place entirely on paved walking and biking paths, with no road closures required. Two water stations are provided on course: one at the 2-mile mark for both races, and another at the 4-mile mark for the 10K.
The 1K Kids Run is a short out-and-back on the Marymoor Connector Trail. Parents are welcome to run with their children without registering.
Participant Information
All participants receive a short-sleeve participant shirt, a custom race bib, and a timing chip. Awards are downloadable finisher certificates that include age group placement; no physical awards are given.
Parking is free in the designated Cirque Lot. Dogs on leashes and strollers are permitted on the course. Visit the organization's website for the most recent information.
