About UltraRunTrack

What Ultraruntrack Is

Ultraruntrack is a live position tracker for ultramarathon races. It shows where runners are on course right now, based on timing data races publish at official checkpoints.

Most elite ultramarathons—Badwater 135, Western States 100, and others—do not use GPS. Race organizers publish split times at official stations spaced 17 to 42 miles apart. That is the only official data.

Ultraruntrack takes those checkpoint times and estimates each runner's position between stations. It fills the gap between checkpoints so you can watch the race unfold.

The Problem It Solves

When a race publishes its first checkpoint, you know who is in front. You have no idea where they are 20 minutes later.

For fans, that is boring. For crew, it is a planning problem. For race analysis, it is a hard stop.

Ultraruntrack solves this. Crew can see when their runner approaches their station. Analysts can track pace trends live. Race fans can watch the race as it happens.

How Position Estimates Work

Position between checkpoints is estimated using three inputs:

• Historical pace for each course segment, taken from median pace over that stretch in previous races.
• Adjustment for each runner's current form. Runners running faster than their historical average get an optimistic estimate. Runners falling behind get a conservative one.
• Recalibration at every checkpoint. When a runner reaches the next checkpoint, the real split time replaces the estimate.

This method has been backtested against archived race data. Mean error is roughly 1 mile between checkpoints.

The site never projects a runner past a checkpoint not yet reached. It never ranks runners with no confirmed split. When multiple runners share an estimated position, they appear as a single pack marker, not invented separation.

Accuracy and What We Won't Do

Estimates answer a simple question: roughly where is this runner right now. They are not precise. They are honest.

We do not invent data. If a runner has not reached a checkpoint, we do not guess. If we lack historical data for a segment, we use conservative pace estimates.

We do not rank runners with no confirmed split, and we do not show a projected finish or an average pace until a runner has cleared a real checkpoint. Once they have, we do show a projected finish, clearly labelled as a projection.

They work because most ultrarunners hold a steady pace over familiar terrain. They break down in extreme conditions, major mechanicals, or when a runner changes strategy mid-race.

Free, No Accounts, No Tracking

Ultraruntrack is free. No accounts. No login. No cookies, analytics, tracking pixels, or personal data collection.

Traffic is measured from server logs only. An optional email list notifies you when the next race is tracked. That is the only data collected, and only if you opt in.

Independent and Unaffiliated

Ultraruntrack is an independent fan project. It is not affiliated with, endorsed by, or connected to any race organizer or timing partner.

Timing data comes from races and their official timing partners. For Badwater, that is AdventureCORPS. We use their publicly published data.

We are not a race service. We are a fan project built by Forge Built AI.

Adding Your Race

If you run a race or manage its timing, email hello@ultraruntrack.com.

We can track any race that publishes split times at official checkpoints and consents to live tracking and analysis.

Who Built This

Ultraruntrack is built and operated by Forge Built AI, a systems studio that builds AI-driven tools for specific problems in specific industries.

This site is both a free public service and a live demonstration of our work. Learn more at https://forgebuiltai.com.