Both vehicles were traveling southbound on Hwy. 259 South when the pickup, driven by Terry Larimore of Leitchfield, crested a hill to find the wagon and horses.
He told police he was unable to avoid hitting the wagon, driven by Jerry Major of Falls of Rough.
Major was thrown to the roadway with "obvious head trama" according to nurse Robin Grant of Harrodsburg who arrived on the scene shortly afterward.
Major was transported to Twin Lakes Regional Medical Center by Grayson County EMS, then flown by StatCare to University Hospital in Louisville.
A University spokesperson listed Major in serious but stable condition Tuesday, Sept. 2.
Twin Lakes Animal Hospital and Leitchfield Vet Clinic responded to care for the animals. Both horses were injured, one fatally.