The Underground Circus 100 offers runners an unforgettable ultra trail experience on the scenic Silver Comet Trail near Smyrna, Georgia. This challenging yet straightforward course features five miles out and back along both trail paths and paved sections, giving participants a unique blend of terrain to tackle. Race day begins early at 4 AM when runners set off from the starting line under the guidance of race directors who ride bikes ahead to ensure everyone stays on track. The route is simple: head straight out for five miles before turning around and retracing your steps back to the start-finish line, making it easy to navigate without getting lost. Aid stations are strategically placed at both ends of the course—starting line and halfway point—to provide essential supplies like water, hydration mixes, snacks, and energy drinks. Runners can also rely on a second aid station mid-way through for additional support. Participants have complete freedom over their pacing; there are no strict time limits or mandatory cut-off points to adhere to. This flexible approach allows runners to push at their own pace while still enjoying the scenic beauty of Georgia’s countryside and the camaraderie among fellow endurance athletes. The event is committed to honoring each mile run, with finishers earning recognition regardless of how long it takes them to cross the line. The 100-mile distance culminates in a customized brass buckle for those who complete this grueling challenge, while shorter distances also come with their own unique awards and souvenirs. For convenience, Smyrna’s Silver Comet Trail is just a twenty-minute drive from nearby airports and close to hotels and restaurants, making it easy for participants to find accommodations before the race. Parking options are available but without electrical hookups; however, runners can bring vans or RVs if needed. Volunteers who complete a full 12-hour shift during the event receive free entry into next year’s Underground Circus 100 as part of their reward package. This spirit of community and support underscores the race's commitment to fostering a supportive environment for all participants and volunteers alike. The Underground Circus 100 is more than just an ultra trail run; it’s a celebration of perseverance, scenic beauty, and community camaraderie on one of Georgia’s most picturesque trails.
Races Offered
100 Miles
May 29, 2027
straighten
Distance —
160.9K
terrain
Type —
Running
timer
04:00
sell
$275.00
24HR
May 29, 2027
straighten
Distance —
24 Hours
terrain
Type —
Running
timer
04:00
sell
$250.00
50 Miles
May 29, 2027
straighten
Distance —
80.5K
terrain
Type —
Running
timer
04:00
sell
$150.00
12hrs
May 29, 2027
straighten
Distance —
12 Hours
terrain
Type —
Running
timer
06:00
sell
$125.00
6hrs
May 29, 2027
straighten
Distance —
6 Hours
terrain
Type —
Running
timer
06:00
sell
$89.00
Weather History
These values represent the 3-year monthly averages for May in Smyrna.
thermostatTemperature
16.0° / 26.1°
wb_sunnyFeels like
15.6° / 25.4°
light_mode
Avg sunshine hours
10h 4m
water_drop
Avg rainfall
4.7 mm
ac_unit
Avg snowfall
—
air
Avg wind speed
10.5 km/h (Light breeze)
opacity
Sweat loss rate
High
terrain
Course conditions
Hard and dry surface
sunny
Max UV Index
High (6.0)
humidity_mid
Humidity
72.5%
wb_twilight
Sunrise
06:36
nightlight
Sunset
20:32
About Smyrna
Learn more about the host city, Smyrna.
Smyrna is a city in Cobb County, Georgia, United States. It is located northwest of Atlanta, and is in the inner ring of the Atlanta Metropolitan Area. It is included in the Atlanta–Sandy Springs–Alpharetta MSA, which is included in the Atlanta–Athens-Clarke–Sandy Springs CSA.
