Castle Rock Trail Festival / liveBIG Run

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Come challenge yourself on Castle Rock's vast ridgeline trail system. Trail run options range from the liveBIG 5K to the Ultra Marathon 50K. If you’ve run this trail system before, you know these are some beautiful and beguiling trails.

Race details

Mark your calendar for the first Saturday in October!
Saturday, Oct. 5, 2024

Thanks to all who participated in the 2023 event. Download your 2023 event and participant photos.

Race features

  • All participants will receive an event T-shirt and finisher’s medal
  • Professional chip timing with a disposable bib chip
  • Free photo downloads after the event
  • Post-race refreshments starting at 10:30 a.m.

Race routes

Course options & fees


  • liveBIG Family Adventure Run: $20
  • Philip S. Miller 5K: $35
  • Ridgeline 10K: $45
  • Ridgeline Trail Half Marathon: $65
  • Ridgeline 50K: $95


Register for one of our 2024 Trail Festival events

Race day event timeline

Time Event
6 a.m. Packet pickup and walk up registration
7:30 a.m. 50K race start
8:30 a.m. Half Marathon race start
9 a.m. 10K race start
9:30 a.m. 5K race start
10:30 a.m. liveBIG Family Adventure Run start
3:30 p.m. Finish line closes

More information

Time limit

The 50K Ultramarathon will have an 8 hour time limit. The finish line will close at 3:30 pm. You must start the second loop before 11:30 am or you will not be able to continue.

Aid stations

In an effort to help keep everyone safe, we will be providing bottled water and basic first aid items at each aid station. Additionally, the 50K aid stations at Philip S. Miller Park, and the aid stations at Number 4 and Number 12 on the Ridgeline side, will have electrolytes available.

Food and beverage

The finish line beverages including water, Gatorade and beer.

Drop bags

We will have a 10-foot by 10-foot tent with a tarp on the ground at the start of the second loop of the 50K. This is located right near the finish line. You are more than welcome to take a bag to this location and leave it for the duration of the race.


Overall and age group awards will be presented in all races 5K and up. Top overall male and female, as well as, the top three in the following age groups:

Half Marathon and 10K

  • 19 and under
  • 20 to 29
  • 30 to 39
  • 40 to 49
  • 50 to 59
  • 60 to 69
  • 70 and over

50 Ultra

  • 19 and under
  • 20 to 29
  • 30 to 39
  • 40 to 49
  • 50 to 59
  • 60 and over

Weather and safety information

Natives to Colorado are familiar with the day-to-day weather here. While the average low temperature in early October is 35 degrees and the average high is 65 degrees, please be prepared for anything. We hope to have the perfect weather on race day, but there's always a possibility of rain or snow on the trail making for muddy conditions.

Don't be surprised when running our open space trails. Expect to see rabbits, prairie dogs, deer, fox, coyote, birds, and other wildlife.

If you are traveling from lower elevations, be prepared for some shortness of breath. The high point of the course is 6,700 feet, roughly 1,500 feet higher than the mile-high City of Denver.