Jacob Olivier disappeared without a trace in Everglades National Park in Florida

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(NewsNation) — There has been a critical new development in the disappearance of Jacob Olivier, a young father in South Florida, with a NewsNation investigation revealing that another man had gone missing in the same national park months earlier .

Neither case received media attention. Jacob Olivier's truck was found in Everglades National Park in the summer of 2011, but he's not the only one missing there. Another man with strong family ties also disappeared during a camping trip a few months earlier.

Each year, a million visitors boat, camp, and come face-to-face with alligators in Everglades National Park. But Olivier was a visitor who never returned home.

Jacob Olivier disappears

The Everglades is a popular destination, but Olivier's mother, Laurie Durham, said her son has no ties to the area. She didn't even know he was there, or that he was missing, until a reporter called her.

“I found out about it from a reporter who called me and said, 'Did you know your son is missing in the Everglades?' “, she told NewsNation.

Not only did Olivier have no connection to the park, which covers 1.5 million acres, but he also had no connection to the three South Florida counties it straddles.

Originally from Louisiana, Olivier's truck was found in the Everglades in August 2011. Rangers began searching the park after noticing the vehicle abandoned for days.

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From the start, Durham said he received conflicting information.

“I was initially told there was video of his truck arriving,” she said. “Then I was later told that the video never existed.”

National Park Service notes indicate the 1998 Isuzu pickup truck was parked near Pine Glades Lake.

In the footsteps of Jacob Olivier

Durham said that to his knowledge, Olivier left Spring, Texas, in that truck. He lived there with his father and stepmother and had gone to rehab in the area.

Olivier then traveled to an area near Savannah, Georgia. It was a place he had once called home and he hoped to rekindle a romantic relationship.

But this ex-girlfriend was dating someone new. Olivier is gone.

A receipt from a Daytona Beach, Fla., hotel was found in his truck when rangers discovered it.

Courtenay Yeager, Olivier's sister, confirmed he had no ties to the area. She said he would run away from what she described as a difficult childhood.

“When my mom told me he was missing, I said he probably ran away,” she said. “I was in denial. I said he was going to come back. I was just in shock.

But Olivier wasn't the only one to disappear in the park, shocking his family members.

Roger Sawyer disappears

Just five months earlier, Roger Sawyer, 67, and his extended family stopped their RV in the Flamingo area of ​​the park in March 2011. They were on their way to visit the Florida Keys.

Sawyer's family said the group split up for 20 minutes to stretch their legs and take a short hike. Sawyer, who they said did not have dementia, never returned.

After a week of intense ground and air searches, the hunt for the retired grocer was called off. It's unclear whether the man described as an experienced outdoorsman got lost or if something caused his disappearance.

No leads in either case

Olivier's case also remains a mystery. Durham lovingly looks back on memories of her second son, the happy photos of her child contrasting sharply with the pain of his passing.

Dozens of searchers searched for Olivier for a week, using dogs and helicopters, but found no trace of him. But she doesn't give up.

“I’m still here and I’m going to keep watching until the last breath I have in me,” Durham said. “I'm not giving up. I'll never give up. Until I'm cremated, I'll never give up.

NewsNation reached out to Everglades National Park's law enforcement team for information on both cases. They referred us to the national spokesperson, where a public affairs specialist directed reporters back to the park.

Everglades National Park's communications chief said he was urging people to come forward with relevant information and that both cases were still open.

Requests for public information regarding details were declined.

Jacob Olivier would now be 36 years old and Sawyer 81 years old.