Boulderthon Marathon 2024 Lok. The boulder marathon on sun 29th sep 2024. You’ll start and finish in the iconic running mecca of downtown boulder, with stunning views of the flatirons throughout the course.
You’ll start and finish in the iconic running mecca of downtown boulder, with stunning views of the flatirons throughout the course. After nearly tripling in size and selling out, new 8,000 runner cap.