A treasure-hunting Texas father and son recently found their most precious discovery yet.

Markus Hogue of Austin and his 12-year-old son Gabriel were looking for seashells on Padre Island on the southern coast of Texas on June 1 when they spotted what appeared to be a pile of waste. But they noticed that a bottle was sticking out of the debris.

"My son was out there looking for something to get his mom and his girlfriend and I happened to walk across it," Hogue told USA TODAY Wednesday. "Thought it was trash and it ended up being a message in the bottle."

Gabriel first thought the bottle contained a possible treasure map after seeing drawings of seahorses on it.

"I was very surprised and very happy at the same time," Gabriel told USA TODAY. "All the excitement was just rushing through."

Letter written by parents on a Mexico cruise

Although the verbiage appeared to be German, Hogue, 42, said it wasn't until they opened the bottle that they realized the letter inside was written in Spanish.

"I am sending you this message so that you know how much Mom and Dad love you," the letter reads in Spanish. "I love you daughter, never forget it."

At first, Hogue said he assumed the letter was written for a daughter who passed away.

He decided to text a phone number listed in the letter and got a response within 10 minutes. To his surprise, the intended recipient of the letter is the one who responded, and she was very much alive.

Keyla Collazo of Colorado Springs told Hogue that her parents, who live in Waterbury, Connecticut, wrote the letter to her while they were on a cruise in Mexico last August because she wasn't able to join them.

"They told me that they threw a bottle in the river ... but that's pretty much it," Callazo told USA TODAY. "We didn't think that it'll get somewhere ... It's been a shock. Me and my kids are still talking about it."

Collazo said the father and son could keep the letter

Collazo said she has no problem with Hogue and his son keeping the letter, though Hogue says he'll give it back anytime the family wants it.

Hogue is working on getting it framed, along with other pictures from his and Gabriel's unforgettable beach trip, he said.

Though the father and son have previously found pieces of gold on other treasure hunts, Hogue said it's the letter that means the most.