Castle Rock Trail Festival / liveBIG Run presented by Hydrate IV Bar

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Come challenge yourself on Castle Rock's vast ridgeline trail system. Trail run options range from the liveBIG Family Adventure Run to the Ultra Marathon 50K. If you’ve run this trail system before, you know these are some beautiful and beguiling trails at both Philip S. Miller Park and Ridgeline Open Space.

Race details

Saturday, October 7
6 a.m. to 3:30 p.m.
Philip S. Miller Park

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

Registration and Fees


  • liveBIG Family Adventure Run: $20
  • Philip S. Miller Park 5K: $35
  • Ridgeline 10K: $45
  • Ridgeline Trail Half Marathon: $65
  • Ridgeline 50K: $95
  • Registration closes Tuesday, Oct. 3. Race day registration is available with a $15 race day fee.

Register for the event

Thank you 2022 participants

Thanks to all who participated in the 2022 event. Download your 2022 event and participant photos.

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 p.m. You must start the second loop before 11:30 a.m. 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 No. 4 and No. 12 on the Ridgeline side, will have electrolytes available.

Food and beverage

The finish line beverages include 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.