Issaquah Schools Foundation Monster Mash 5K

Help us raise a MONSTROUS amount of support for local students on October 24th! ISF Monster Mash 5K is a community-based, family-friendly event that raises funds for programs that serve students attending all 27 ISD schools.

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 walk together as a family! Bring your creativity – festive costumes are encouraged!

This event sells out every year, so don't wait to register! Every registration submitted by October 12th receives a 2026 Monster Mash technical race tee & medal. Registrants receive free event photos and raffle tickets for prizes as well! Placement awards for fastest finishing times will also be presented. See below for details.