100mi events in Colorado, United States
Find 100mi events in Colorado, United States. Compare 3 upcoming events by date and location. Open a race guide for the course, recorded editions and official entry information where available.
Events to explore include Weld Your Mettle Running Festival, Hardrock Hundred and Front Range Ultra Dayze.
Compare running races by distance, date and surface, from shorter road events to trail races and ultras.
3 listed events · 3 with upcoming dates
Upcoming 100mi events
3 matching events, earliest date first. Entry availability is shown separately.
Weld Your Mettle Running Festival
USAEaton, Colorado
Loop running races and timed endurance challenges near Eaton.
Date listed · latest organiser confirmation not yet checked.
Hardrock Hundred
USASilverton, Colorado
High-altitude 100-mile loop through the San Juan Mountains.
· Status TBC
Date listed · latest organiser confirmation not yet checked.
Front Range Ultra Dayze
USALoveland, Colorado
Multi-day ultras on a two-mile mixed-surface loop through Centennial Park and Rivers Edge Natural Area.
Date listed · latest organiser confirmation not yet checked.
Race archive
Past races and previous editions
Looking back at a race? Browse the guides below for recorded editions. This section also includes events awaiting a new date and cancelled editions. Previous editions of races in the upcoming calendar are available through their race guides above.
No separate archived race guides are listed for this selection yet.
View full race archive (0) →Choosing a race in Colorado
The unfiltered upcoming calendar includes events in Eaton (1), Loveland (1), Silverton (1). Use the town filter to compare locations, then check the race guide for the start venue and organiser’s travel information.
Questions about 100mi events in Colorado
What should I check before a running event in Colorado?
Choose your distance, then check the route, elevation, cut-off time and entry conditions in the organiser’s race guide.
Which 100mi events are coming up in Colorado, United States?
Weld Your Mettle Running Festival is listed for 5 June 2027. Hardrock Hundred is listed for 9 July 2027 (status to be confirmed). Front Range Ultra Dayze is listed for 2 September 2027. Check the race guide and organiser’s latest information before making plans.
Where can I find race entry details for Colorado, United States?
Follow the link from the race guide to the organiser or entry provider, where one is available. Check the entry deadline, eligibility and current availability there. A listed race date does not necessarily mean entries are still open.
Why has a race moved out of the upcoming calendar?
Once its listed dates have passed, a race moves to the past-editions view unless another upcoming edition is recorded. Cancelled events also leave the upcoming list. The race guide stays available, and the event returns when a new date is added.