The Professional Bull Riders say Mason Lowe died Tuesday evening after being taken to a hospital. Group spokesman Andrew Giangola said he was wearing a mandated protective vest.
The 25-year-old from Exeter, Missouri, was ranked 18th in the world.
He was injured while coming out of a chute on a bull weighing about 1,700 pounds (771 kilograms) and attempting to stay on for eight seconds.
A witness told KCNC-TV that Lowe fell off and was stomped as he tried to get up.
Professional Bull Riders CEO Sean Gleason says the group and the stock show extend sympathies to Lowe’s family.