Spectator Guide · Mercer Island Half Marathon, 10K & 5K

Mercer Island Half Marathon Spectator Guide

October 29, 2026 · 3 min read

Large half marathon in Mercer Island. Base at the start/finish area.

In this guide

At a glance

Date
Friday, March 26, 2027
Distances
Half Marathon, 10K, 5K
Field size
About 4,500 runners
Registration
raceentry.com

The Mercer Island Half Marathon is a large field event in Mercer Island. Spectators should base at the start/finish area.

Best places to stand

  • Start/finish: Mercer Island start and finish area.
  • Course: sidewalks along the published route.

Getting there

Use the official parking and closure information. Arrive early.

Where to meet

Agree on a landmark outside the finish chute.

Keep exploring

Common questions

When is the Mercer Island Half Marathon, 10K & 5K?
Friday, March 26, 2027.
How do I register for the Mercer Island Half Marathon, 10K & 5K?
Registration is handled by the organizer at raceentry.com.