Lake Sammamish Boat Launch
4455 East Lake Sammamish Pkwy SE
Issaquah, WA 98029
Thank you for joining us for Monster Mash 5K!
You helped us raise a MONSTROUS amount of support for local students!
Each year, ISF Monster Mash 5K raises funds for programs that serve students attending all 27 ISD schools.
2025 MONSTER MASH INFO
EVENT
We welcome all-ages and abilities. Convenient onsite parking, phased start times, and a professionally chip-timed course ensure a great experience for all. You’ll appreciate the flat, paved, out-and-back route whether you’re setting a new 5K PR or enjoying a brisk morning walk together as a family! Bring your creativity – festive costumes are encouraged!
REGISTRATION PERKS
Every registration submitted by October 12th receives a 2025 Monster Mash technical race tee & medal. All registrants receive free event photos and raffle tickets for prizes as well! Placement awards for the top finishers will also be presented.
Monster Mash is a nonrefundable, all-weather event – Rain or shine, we’ll see you there!
Early Packet Pickup: Save time & Sleep in on Race Day!
Skip the lines on race day by picking up your packet early at the Issaquah Schools Foundation on Friday, 10/24/25, anytime between 4-7 PM. Can’t make that time work? Enlist the help of friends – it’s OK to pick up packets for others! Since parking is limited in front of the ISF building, please see overflow parking area highlighted in yellow here.
MM5K Photos
