A Montana horseback rider who vanished during a ride along a recreational trail was found dead in a lake Tuesday afternoon, the sheriff’s office said.

The frantic search for Meghan Rouns ended in tragedy when her body was pulled from 11-feet deep water in Upper Hauser Lake, Lewis and Clark County Sheriff Leo Dutton told The Post in an interview.

The 27-year-old woman disappeared after she and her horse went out for a ride Friday afternoon. She took a photo for social media shortly after 4 p.m. that day but was reported missing that night after her family hadn’t heard from her.

So far, foul play is not suspected, though Dutton, who is also the county coroner, still needs to conduct an autopsy to determine the manner and cause of death.

“Her Husband, his family and Meghan’s family wish to thank all of you who helped search for her,” Dutton said in a statement announcing the death.

“You held out for hope and gave them comfort that they were not alone in this ordeal.”

Dutton said one theory investigators are looking into is whether Rouns fell off her horse and into the water because of gusty winds in the area during her ride.

Her horse and cellphone were discovered during the search for her on Saturday, authorities previously said.

The sheriff’s rescue effort turned into a recovery mission Monday, the sheriff said.