Ultrapalooza, part of the prestigious Kansas Super Slam of Ultrarunning Series, invites runners from across the nation to experience one of the flattest and most scenic trail races in the Midwest. Hosted by Midwest Endurance, this event takes place along the iconic Flint Hills Trail, which winds through some of America's last remaining tallgrass prairie ecosystems. The race course offers a unique blend of terrain including old railroad beds and towpath trails, providing runners with spectacular views of rolling farmland, riparian woodlands, and towering bluffs alongside the Marais Des Cygnes River. The trail itself is entirely flat and covered in crushed gravel, ensuring an efficient yet challenging ultra-distance experience. Scheduled for late September, Ultrapalooza promises a moderate climate but also highlights the potential unpredictability of Mother Nature; temperatures can range from cool to surprisingly warm, with average highs around 84 degrees Fahrenheit and lows averaging at 63 degrees. Runners are encouraged to stay informed about weather conditions leading up to race day. The event offers various distances including a full marathon, half marathon, 50K, 50-mile run, and the ultimate challenge: a 100-mile ultra. Each distance features well-stocked aid stations manned by knowledgeable staff every four miles or less on average. Customized technical shirts are provided to all participants who register early enough. The race hub is located at Mile Zero of the Flint Hills Trail in Osawatomie, where runners will be greeted with cowbells and cheers from spectators as they cross the finish line. This area also serves as a central location for crew support, complete with music, food trucks, restrooms, and ample space to set up camp. Awards are presented based on gender overall standings in each distance category, along with unique hardware that celebrates the spirit of endurance running. While there is no official photographer assigned, event organizers collaborate closely with local photography enthusiasts who capture both scenic highlights and runner moments throughout the race course. Crew access points allow for efficient drop bag placement and crew interaction at designated aid stations. Pacers are permitted only on longer distances beyond specific mile markers but must adhere to strict guidelines regarding assistance and supplies. With a 30-hour time limit set for the full marathon distance, runners will have ample opportunity to enjoy the diverse landscapes while pushing their limits in this unforgettable ultrarunning experience.
Races Offered
100 Miler
Sep 26, 2026
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Distance —
160.9K
terrain
Type —
Running
timer
06:00
sell
$240.00
100K
Sep 26, 2026
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Distance —
100K
terrain
Type —
Running
timer
06:00
sell
$190.00
50 Miler
Sep 26, 2026
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Distance —
80.5K
terrain
Type —
Running
timer
06:00
sell
$180.00
1/2 Marathon
Sep 26, 2026
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Distance —
21.1K
terrain
Type —
Running
timer
06:30
sell
$70.00
50K
Sep 26, 2026
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Distance —
50K
terrain
Type —
Running
timer
06:30
sell
$110.00
Marathon
Sep 26, 2026
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Distance —
42.2K
terrain
Type —
Running
timer
06:30
sell
$90.00
10K
Sep 27, 2026
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Distance —
10K
terrain
Type —
Running
timer
07:00
sell
$50.00
5K
Sep 27, 2026
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Distance —
5K
terrain
Type —
Running
timer
07:10
sell
$40.00
Weather History
These values represent the 3-year monthly averages for September in Osawatomie.
thermostatTemperature
16.8° / 27.9°
wb_sunnyFeels like
16.4° / 27.4°
light_mode
Avg sunshine hours
10h 26m
water_drop
Avg rainfall
3.1 mm
ac_unit
Avg snowfall
—
air
Avg wind speed
9.9 km/h (Light breeze)
opacity
Sweat loss rate
High
terrain
Course conditions
Hard and dry surface
sunny
Max UV Index
Moderate (5.0)
humidity_mid
Humidity
66.5%
wb_twilight
Sunrise
07:02
nightlight
Sunset
19:26
About Osawatomie
Learn more about the host city, Osawatomie.
Osawatomie is a city in Miami County, Kansas, United States, 61 miles (98 km) southwest of Kansas City. As of the 2020 census, the population of the city was 4,255. It derives its name as a portmanteau of two nearby streams, the Marais des Cygnes River and Pottawatomie Creek.
