The West Australian horse racing industry is reeling after the death of popular trainer Hana Dickson in a riding accident.

The WA Racing Trainers' Association said it's understood the 31-year-old was riding at a property in Hopeland on Saturday when she may have hit a tree.

She was later discovered by stable foreman Aaron Pateman.

WARTA president Trevor Andrews said Ms Dickson was about to return to racing at Belmont with one of her horses Disciple, after taking a break for a couple of years.

Mr Andrews said the industry was shocked and deeply saddened by the death of the popular trainer.

"Hana was respected by her peers after being involved in training for about ten years," he said.

"Everybody is just so shocked.

"She died doing what she loved, but she was too young."