'Just let us know:' West Allis parents searching for son, a U.S. Marine veteran and firefighter, who went missing in March

WEST ALLIS, Wis. (CBS 58) -- If you walk into Karie Valona's home in West Allis, the first thing you'll see are the dozens of family photos that cover the walls in her living room and kitchen. 

Among the images is more artwork of the family, beautifully handmade by Valona's grandchildren. 

"There he is with his three sisters!" Valona exclaims, while pointing out some of her favorite pictures. "This, again, was when we were just down there in November."

She and her husband, Tony, are the proud parents of four children -- three daughters and one son -- and it's clear for the Valonas, that family is everything, which is what's made the past almost two months so hard.

Their son, Bret, was last seen March 1 when he was dropped off by his siblings at the Eastern Lake Trailhead in Point Washington State Park in Florida.

The 36-year-old is a U.S. Marine veteran who served two tours in Iraq, and who then worked as a firefighter in the southwest for four years.

He's also trained in survival skills and has previously preferred to live a nomadic and outdoor lifestyle.

But it's because he likes to travel and go off of the grid that the Valonas implemented a "three-week check-in" which Bret has now missed in uncharacteristic behavior.

The Valonas last heard from him during a call on March 1, Karie's birthday, where he called to wish her well.

"Sounded perfectly fine," Valona said.

He texted his cousin's wife the day after, but since then there's been radio silence, and his phone is untraceable.

"Unfortunately, in October, he lost his service dog, and I think that started maybe some of the spiraling," Valona said. 

Over the last several weeks, there have been multiple search efforts by strangers and the Walton County Sheriff's Office alike.

A GoFundMe to help aid in the search has also raised nearly $7,000. 

Others have also started a Facebook page to keep track of updates.

Now the Valonas are heading down to Florida as well, and plan to stay through at least the next week hoping for a sign from their son, although they are unsure if he is still even in that area.

"We have no idea if he committed suicide or he got hurt out there, or he's just off grid somewhere just starting a new life," Valona said. "Just let us know you're okay, let us know, let us know."

Florida officials said at this point, there is no sign of foul play or that Valona is in danger.

He was last seen wearing a flannel shirt, Dickies khaki pants, and had a yellow rain jacket.

If you have any information about Valona's whereabouts, you're asked to contact the Walton County Sheriff's Office at (850)-892-8111.