Duane Ollinger, who starred on the Discovery Channel series “Mystery at Blind Frog Ranch,” has died. He was 68.

The reality TV star died Tuesday at a Texas hospital following a battle with amyotrophic lateral sclerosis (ALS), a family source told TMZ.

The Texas oilman was a fan-favorite on the show, which followed Duane and his son Chad on the hunt for a legendary cache of lost Aztec gold.

The father-son duo believed the treasure was hidden beneath their sprawling Utah property.

According to his Discovery Channel bio, Duane made a fortune as a high-risk oil contractor, but used that money to dedicate his life to the gold mining opportunity in the Uintah Mountains.

He was convinced that the treasure was below his Blind Frog Ranch and went against locals in the area who told him a curse protects the treasure.

When the show premiered in 2021, Duane led the charge to uncover the treasure he spent years chasing.

But Josh Feldman — who joined the cast in Season 3 — replaced Duane for Season 6 as he became ill.

Many longtime fans of the show have expressed their sadness after Duane’s passing on social media. Duane’s castmate Ryan Skinner paid tribute to the late star on Tuesday.

“Sad to report that my good friend Duane Ollinger of ‘Blind Frog Ranch’ passed away earlier today. Duane was a force of constant positivity, empathy, & encouragement to everyone,” he wrote via X.

“Whenever we talked he would always say to hell what anyone thinks, go out there and ‘TELL YOUR TRUTH!'”

As for Chad, he left “Mystery at Blind Frog Ranch” last year following a series of legal issues.

In December 2025, he was charged with killing his cellmate after guards at the Clark County Detention Center in Nevada found his motionless body.

Chad was ultimately deemed legally incompetent in January and was ordered to undergo treatment at a mental health facility, per Courthouse News Service.

Season 6 of “Mystery at Blind Frog Ranch” premiered last week and features Feldman and his father taking over the hunt.

New episodes are currently airing weekly on Wednesdays at 10 p.m. ET on the Discovery Channel.