A mare used in the Wild Horse Race at the Cheyenne Frontier Days (CFD) died on Saturday after sustaining a neck injury.

The CFD in Cheyenne, Wyo., features rodeo-style events, living history demonstrations, and music concerts. The Wild Horse Race features teams of wranglers and riders who attempt to saddle and ride horses that have previously had only minimal handling.

The event made headlines last month when Steve Hindi, president of the Illinois-based animal advocacy group Showing Animals Respect and Kindness criticized singer Sheryl Crow for donating proceeds from her July 22 CFD concert to a wild horse advocacy group on grounds that the Wild Horse Race is inhumane.

Bob Budd, CFD spokesman, said the mare sustained a neck injury after the Wild Horse Race on Saturday night.

"The event was over, and the horses were just trotting around the track," Budd said. "It’s unclear whether she stepped on her own lead, or another horse stepped on it causing the injury."

A veterinarian sedated the mare on the track, and the animal was loaded into an equine ambulance, but died en route to treatment, Budd said.

The mare was the second animal to die during this year’s CFD, held July 18-31. On July 23 a horse used in the Rookie Saddle Bronc event was euthanized after sustaining a back injury.