Jackson was working on the family's ranch when the brakes on a flatbed trailer pulled by a Freightliner truck began to lock up.
Jackson crawled under the trailer to work on the brakes, which then released, causing the truck to pull the trailer over Jackson.
Justice of the Peace Mike Heatley was notified and pronounced Jackson dead at the scene.
Ranger Medic Service and Stephens County Sheriff's office deputies responded to the scene.
Jackson was a Breckenridge High School and Texas A&M University graduate.
He is survived by his wife Shelby and infant daughter Addalyn.