September 21 - 22, 2024


1400 South Street

Osawatomie, KS 100 Miler, 100K, 50 Miler, 50K, 1/2 Marathon, 10K, 5K

Registration closes: Sun, Sep 22 @ 11:59PM CT


Ultrapalooza is part of the Kansas Super Slam of Ultrarunning Series.

Midwest Endurance brings you Ultrapalooza! It’s the flattest, awesome-est, running-est party in the Midwest! The trail crosses the beautiful Flint Hills. The Flint Hills represent one of the last remaining tallgrass prairie ecosystems in the world. The eastern portions of the route travels alongside the Marais Des Cygnes River, between rushing waters and towering bluffs, through rolling farmland and riparian woodlands. The Flint Hills Trail is the seventh-longest rail-trail in America, and the longest trail in Kansas. It follows the general route of the Santa Fe National Historic Trail and forms a component of the coast-to-coast American Discovery Trail. Cool, huh?

The race will be held in late September. The average high temperature is 84 degrees with an average low of 63 degrees. Although fall weather is typically beautiful, mother nature can be unpredictable. Record highs have reached triple digits. Be prepared for anything. Make sure you check the weather reports leading up to race day.

~ The course is entirely on a flat, fast, crushed gravel trail, with manned and unmanned aid stations no more than 5.0 miles apart making is a great ultra experience!

~ Customized unisex technical blend race shirts for all racers. You must register by September 5th to guarantee your shirt size.

~ Abundantly stocked aid stations and knowledgeable aid station captains.

~ Hammer swag bag with product.

~ Great Distance-specific hardware.

~ Unique Awards for the Top M/F Overall in all distances.

~ We're thankful to have the help of our photographer friends to capture not only the course itself but the spirit of our homegrown event.


All races will start and finish at the Mile 0 Flint Hills trail head in Osawatomie. This will also serve as the main hub of the race. We’ll have cowbells ringing and people screaming as runners finish an amazing endeavor! The Start/Finish is a great area for crews to hang out. We will have music playing and a food truck all night. There are also restrooms located in this area.

30 hour time limit for the 100 miler and 100k
100 miler turn around will close at 9:00pm.
Race closes 12:00pm Sunday.

30 hours for 50 miler
50 miler turn around will close at 4:00am
Race closes 12:00pm Sunday.

12 hour time limit for the 50K
Race closes at 6:30pm Saturday.

6 hour time limit for the Half
Race closes at 1:00pm Saturday.

Late Registration will be available at Friday Packet Pickup and on Race Day. Race day registration will begin at 5:30 AM. Shirts and swag are not guaranteed for late entries.

Course Description

The course will be an out and back consisting of single track trail, old railroad beds and towpath trail. It is home to abundant prairie plant and wildlife species, spectacular views, national historic sites, and a diverse set of recreational areas. It is flat, crushed gravel course. Don't worry, you won’t get lost. The course is mostly straight, staffed well, and marked the best.

Aid Stations

Manned aid stations are fully stocked with water, hammer nutrition heed electrolyte drinks, snack foods, sandwiches, chips, candy, hammer gels, and more. Unmanned stations will be water only. Approximate distance between aid stations is no more than 4 miles.

Schedule of Events

Friday, September 21st
4:00-7:00pm Packet Pickup

Saturday, September 22nd
5:00-5:45am 100 mile/100k/50 mile Race Day Packet Pickup
5:45am Pre Race instructions/ National Anthem
6:00am 100 mile/ 100k/ 50 mile RACE START
5:45-6:15am 50K Race Day Packet Pickup
6:30am 50K RACE START
6:00-6:45am Half Race Day Packet Pickup
7:00am Half START
1:00pm Half CLOSES
6:30pm 50K CLOSES

Sunday, September 23rd
12:00pm 100 Miler, 100k, and 50 Miler Races CLOSE
12:01pm Awesome people help with tear down

Race Rules

We are guests of the Flint Hills Trail and the Kanza Rails-Trails Conservancy and must follow all rules. Any violation of these rules will be grounds for disqualification from the race:
1. All pets must be kept on a leash.
2. Littering is strictly prohibited.
3. Runners must stay on designated trail at all times.
4. Runners must be respectful of all volunteers and park staff.
5. Crew must only meet runners at designated crew access aid stations.

Medical Form

!!!!!MEDICAL FORM!!!!!
Our Medical Director has asked that you read over the Medical Information for Runners, then fill out the Medical Information Sheet. All runners will be required to turn in a completed Medical Information Sheet at Packet Pickup. This will allow us to better assist runners and to alert aid station captains of any specific help that may be necessary. Your assistance with this is very much appreciated. Help us, help you!


Pacers will be allowed for the 100 mile, 100k and 50 mile distances only.
No pacers allowed before mile 50 for the 100 miler, 31 miles for the 100k or mile 25 for the 50 miler.
Only one pacer at a time per entrant.
Pacers may not mule/carry supplies for their runner.
All pacers must sign a liability waiver.
All pacers must wear a “pacer” bib while with their runner.
Pacers must be over 18 years of age or have the signed permission from a parent/legal guardian.
Pacers are allowed to help themselves to any food and beverages at aid stations while they are pacing. Pacer bibs and waivers will be at the crew access aid stations. Pacers can only enter/exit the race at manned aid stations.

Drop Bags

There will be a drop bag area available during packet pickup for all manned aid stations. Please keep all drop bags to a reasonable size. You are limited to one drop bag, per manned aid station, one per person. Your drop bag MUST be clearly marked with the following information:
~ Your Name
~ Race bib number
~ Race distance
~ Aid station name
Runners can also place their drop bags in the designated areas on race morning by 6:15am. We cannot ensure timely delivery if you drop your bag after 6:15am. Drop bag locations will be clearly marked with aid station locations. Start/Finish area will provide plenty of area for your crew to set up during the race, with music, restrooms, and lots of camaraderie as they await your passing and then your finish! Drop bags will be returned to the Start/Finish area by 12:00pm on Sunday. We will try to have them back sooner on a rolling basis but can only completely guarantee a noon delivery.

Refund Policy

WE HAVE A NO REFUND, NO TRANSFER POLICY FOR THIS RACE, HOWEVER, runners may defer their race entries to the same race the following year by notifying the Race Director a minimum of 10 days prior to the event. Deferral will not be permitted for any runner making a request less than 10 days before the scheduled event and we do NOT offer refunds. The race deferral is good for one year only. Requests for deferral must be submitted to the Race Director by email, communicating through the UltraSignup registration site.

Dropping Down/Changing Distance

You are able to move from one distance to another prior to the event. If you would like to downgrade to a shorter distance, you can, but will not receive a refund. If you would like to upgrade, your original order will be removed and you will be given a credit to re-register for another distance, at the price of the other distance on the date of the original order.

Although it is highly discouraged, we understand that things happen during an ultra-marathon that may force you to not complete the original distance registered. We also want to acknowledge the amount of dedication, commitment, hard work and sacrifice you have put into training for an ultra-marathon. At the discretion of the Race Directors, you may be allowed to drop down and finish in the next lower distance – 100 milers to 100K, 100K to 50 miler, and 50 miler to 50K. You will not be eligible for race placement and will be recorded as an unofficial time.


There are a number of opportunities to volunteer race weekend. If you are interested in contributing to this great event, please send an email to and we will work with you to figure out how you can best help make this race experience even better for the runners.

Event's current local time: 11:44 AM CT


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