A family in southwestern Ontario is looking for the owner of a wedding dress that was found alongside a busy highway.

On Saturday, Katie Predon and her family were leaving a rest area on the eastbound side of Highway 401 in Cambridge, Ont., when they spotted a wedding dress box in a ditch.

They drove a little further and spotted the gown, so they decided to pull over.

“We just noted the one stain on it, but overall it looked like it was in decent shape, so it must not have been there for very long,” Predon said.

Predon and her family scooped up the dress in the hopes of finding its owner and reuniting them with what they think could be a priceless family heirloom.

"Looking at the age of the dress, we figured that it was probably something that held some sentimental value to somebody,” Predon said.

“If it was my mother's wedding dress, I would be distraught,” she added.

Terra Eykens of Sophie’s Gown Shoppe in nearby Kitchener, Ont., says the dress and its gold box are likely several decades old.

“This is a very old box,” she said. “Most boxes that you see now are usually white cardboard.”

“It's a sheath dress and it's got the front pleating, which is characteristic of the 70s,” the store’s manager, Chelsey Nikkel, added. “The sheet lace is very expensive.”

Other details, Nikkel said, point to the dress being handmade.

"There's no boning or anything like that, so there's no real structure to it,” she said.

“They probably feel awful if they've kept it for this long, and it's a really beautiful dress,” she added.

"For someone to keep that heirloom for so long, it definitely means the world to someone," Eykens added. "It’s heartbreaking."

With a report from CTV Kitchener’s Daryl Morris