Sun, Sep 27, 2026

RMRR Fall Marathon Training Series #3

Thornton, CO

Registration openAnnual since at least 2023
10 Miles20 Miles

Entry is $20 now and rises to $25 after Sep 21, 2026, so registering before then saves $5.

Register

About the RMRR Fall Marathon Training Series #3

The course runs out of Riverdale Ballfields, a park with a covered registration area and public restrooms on site. Beyond that, the organizer has not published much about the route itself, so expect a setting that fits a ballfields complex, likely open and relatively flat.

Free race emails

Get the Weekly RunSesh

In for this one or still deciding, keep race season near Thornton on your radar: a Monday look ahead and a Thursday rundown of the weekend's races.

Two helpful emails per week. No spam. Unsubscribe anytime.

Distances & Start Times

10 Miles9/27/2026 07:00$20
20 Miles9/27/2026 07:00$30

Going for a Time?

Set a goal and get a pace band: every mile split on a card sized for your phone lock screen, so race morning needs no math.

Plan Your Trip

Where to Stay

Traveling for this race? The map shows hotels and rentals in and around Thornton — pan or zoom to compare what's nearby.

The map is provided by Stay22. If you book through it, RunSesh may earn a commission at no extra cost to you — it never affects the races we list.

Share Your Card

We made you a ready-to-post image. Story fits Instagram and TikTok Stories; Post fits the feed. Download it, post it, and tag @runsesh so we can cheer you on.

Preview of your share card