Unbound Gravel, formerly known as the Dirty Kanza, is an event comprising gravel racing covering various distances held annually during the late spring on rural roads in the Flint Hills region of the Great Plains around Emporia, Kansas, United States.

[6][7] [8] Starting and ending in Emporia, the routes runs along rural roads in the Flint Hills of east-central Kansas.

[10] There are checkpoints spaced about 50 miles apart for longer races, and riders must carry water and food, as well as fix their own tires and bikes.

[11][12] If riders receive outside support at any location other than official checkpoints it will result in immediate disqualification.

[3] Originally, the event was started as a 200-mile (320 km) mile race, but over the years additional lengths have been added to encourage more riders to give it a chance.

First the races were postponed from May 29–31 to September 10–13 because of the ongoing worldwide COVID-19 pandemic issues,[19] then later were cancelled.

[23] The ensuing controversy resulted in his eventual firing by the event's parent company, Life Time Fitness.