Sign up and verify details on the organizer's official page.
Race feel
Chase a summer PR on a fast, scenic paved loop under the stars at Lake Travis, with distances from 5K to 52.7 miles.
Scenic
Competitive
Experience the Austin Solstice Circuit Challenge, a unique summer ultramarathon designed for speed and personal bests. Run on a smooth, paved 1.64-mile loop through the scenic Texas Hill Country, with Lake Travis as your backdrop. The evening start times for longer distances offer cooler temperatures, allowing you to chase a PR or a Boston Qualifying time under the rising Buck Moon. This event offers distances from 5K to 52.7 miles, catering to various goals.
What to expect
Run a perfectly engineered 1.64-mile paved loop with minimal elevation, designed for speed.
Enjoy breathtaking views of the Texas Hill Country, majestic oak trees, and Lake Travis.
Benefit from an evening start for cooler temperatures, especially for longer distances.
From the organizer
Austin Solstice Circuit Challenge
The Fastest Summer Ultramarathon in Texas
July 25 & 26, 2026 | Pace Bend Park, Lake Travis
Set a PR!
Scenic Hill Country Course
Experience the breathtaking beauty of the Texas Hill Country as you run on smooth paved roads winding through majestic oak trees. With Lake Travis as your backdrop, this picturesque route combines natural beauty with the perfect running surface for speed and comfort.
Set your sights on a personal record at the Austin Solstice Circuit Challenge. This unique event features a perfectly engineered 1.64-mile paved loop with an elevation gain of just 33ft at scenic Pace Bend Park on Lake Travis, designed for speed and performance even in July.
Race Distances
52.7 Mile Race
Loops: 32
Distance: 52.7 mi
Start: 7:00 PM 07/25
50K
Loops: 19
Distance: 31.0 mi
Start: 7:00 PM 07/25
Marathon (USATF Certification code: TX25015LAB)
Loops: 16
Distance: 26.35 mi
Start: 7:00 PM 07/25
25K
Loops: 10
Distance: 15.5 mi
Start: 7:00 PM 07/25; 7:00AM 07/26
10K
Loops: 4
Distance: 6.2 mi
Start: 7:00 PM 07/25;
7:00 AM 07/26
5K
Loops: 2
Distance: 3.1 mi
Start: 7:00 PM 07/25
7:00 AM 07/26
Carpe Diem 60
One Hour. One Sunrise.
Standout details
USATF Certified Marathon (Boston Qualifier)
Evening start for cooler temperatures
Personal pacers welcome for ultras
Custom finisher medals and challenge coins
Perks & features
Awards
USATF Certified
From the public listing; confirm on the official site.
Course feel
A practical read on terrain, elevation, footing, and typical conditions.
Demanding Day
Typical course trends
Typically hilly
Mostly paved footing
Distances & registration
11 options
Use the official signup link above for all distances.
25K
2 options · closes Jul 25, 2026, 7:59 PM CDT
2mo 26d 21m left
Run
Closes Jul 25, 2026, 7:59 PM CDT · From $75.19
Night Run
Closes Jul 24, 2026, 7:59 PM CDT · From $64.59
5K
2 options · closes Jul 25, 2026, 1:00 PM CDT
2mo 25d 17h 22m left
Night Run
Closes Jul 24, 2026, 7:59 PM CDT · From $32.79
Run
Closes Jul 25, 2026, 1:00 PM CDT · From $32.79
10K
2 options · closes Jul 25, 2026, 1:00 PM CDT
2mo 25d 17h 22m left
Night Run
Closes Jul 24, 2026, 7:59 PM CDT · From $43.39
Run
Closes Jul 25, 2026, 1:00 PM CDT · From $43.39
Marathon
1 option · closes Jul 24, 2026, 7:59 PM CDT
2mo 25d 21m left
General entry
Closes Jul 24, 2026, 7:59 PM CDT · From $75.19
50K
1 option · closes Jul 24, 2026, 7:59 PM CDT
2mo 25d 21m left
Run
Closes Jul 24, 2026, 7:59 PM CDT · From $85.79
52.7 Miles
1 option · closes Jul 24, 2026, 7:59 PM CDT
2mo 25d 21m left
52.7 Mile Solo
Closes Jul 24, 2026, 7:59 PM CDT · From $106.99
Other options
2 options · closes Jul 25, 2026, 7:59 PM CDT
2mo 26d 21m left
Pacer Registration
Closes Jul 10, 2026, 7:59 PM CDT · From $16.90
Carpe Diem 60: The Sunrise Hour (One Hour)
Closes Jul 25, 2026, 7:59 PM CDT · From $43.39
Built from public event details. Confirm schedule, fees, and rules on the official event page before signing up.
Unlike typical Texas summer ultras with brutal heat and technical trails, our smooth asphalt loop with minimal elevation gain creates ideal conditions for record-setting performances. This is a USATF-certified course: Certification code: TX25015LAB.
Evening Start Format
Race as the sun sets and July's magnificent Buck Moon rises over the limestone bluffs. Our strategic evening start times for longer distances mean cooler temperatures when you need it most.
Pacers Allowed
While we won't be providing official pacing groups for the Austin Solstice Circuit Challenge due to our size, we enthusiastically welcome personal pacers for both the Marathon, 50K and 52.7 Mile Solo events. Personal pacers can join Marathon and 50K participants after 8 loops and 52.7 Mile runners after 16 loops (approximately halfway points). Each pacer must pay a $15 fee that covers park entry, administrative costs, and an official pacer bib. Pacers need to sign a waiver and wear their designated "PACER" bib while on course. Runners are responsible for arranging their own pacers, but the loop format makes it particularly convenient for your support crew to join when you need them most. We find this flexibility is especially appreciated by first-time marathoners and ultra runners who benefit from personalized support during the challenging later miles as day turns to evening.
Pickup Information:
Saturday Packet Pickup:
Available from 4:30 PM to 6:30 PM.
Race Day Pickup:
For those unable to attend on Saturday or who prefer to pick up on race day, same-day packet pickup will be available Sunday morning from 5:30 AM to 6:30 AM.
Carpe Diem 60
One Hour. One Sunrise. Start your day with purpose.
Carpe Diem 60 is a 60-minute sunrise endurance challenge on this out-and-back course. At 6:00 AM, you’ll have one hour to cover as much distance as possible with early morning focus. Most Distance Covered Wins
Beat the heat. Seize the morning. Earn your day.
Course Details
The distinctive figure-8 course winds through the breathtaking Hill Country landscape of Pace Bend Park, featuring limestone bluffs, majestic oak trees, and views of Lake Travis. The smooth asphalt surface throughout makes it perfect for both day and night running, with the main loop connecting to a smaller upper loop.
Surface: 100% smooth, paved asphalt – ideal for consistent pacing
Elevation: Minimal gain per loop – gentle, predictable terrain
Loop Length: 1.64 miles in a figure-8 configuration
Scenery: Limestone bluffs, oak-covered hills, and Lake Travis views
Aid Station: Access every 1.64 miles at the start/finish hub
Marking: Fully marked with reflective markers for nighttime visibility
"Whether you're chasing a PR, a qualifying time, or simply want to experience the joy of running fast through a Texas summer night beneath towering oaks and limestone cliffs, the Solstice Circuit Challenge offers a rare opportunity to push your limits under optimal conditions."
Amenities
Aid Station
Fully stocked station at the start/finish hub
Restrooms
Convenient toilet vault facilities
Camping
First-come, first-served sites surrounding the course
Parking
Multiple areas for easy access
Finisher Awards
Medals and custom challenge coins for all finishers
Commemorate your achievement with a premium custom-designed medal featuring Lake Travis. These coins are part of the Race Austin Series: Collector's Challenge , which allows you to exchange three same-tier coins from different Fit Foundation races for a complimentary race entry of the same tier.
Join Us for an Unforgettable Experience
Race from sunset to stars beneath the Buck Moon on the fastest summer ultra course in the Texas Hill Country.
REGISTER NOW!
Ready to prepare? Check out our comprehensive training guide designed specifically for the Solstice Circuit Challenge.
Scenic
Competitive
Awards
USATF Certified