Long before René-Lévesque Boulevard became one of Montreal's busiest streets, it was home to a Protestant burial ground where some of the city's early Scottish settlers paid tribute to their dead.

Hydro-Québec workers installing a new electrical line recently uncovered 40 skeletons at the site of the old cemetery, which was situated between what is now Jeanne-Mance and St. Urbain streets.

Two of the skeletons were found intact, protected by what remained of their wooden coffins, said André Burroughs, an archeologist with Hydro-Québec.

"It's a small window we're opening on Montreal history," he said in an interview. "It gives us an idea of how the city developed."

An 1825 map shows the site of the old burial ground. (Hydro-Québec)

The cemetery was in use between 1799 and the middle of the 19th century. At the time, the area was a suburb of Montreal; what is now Old Montreal was the original city centre.

This one-time suburb is now home to towering sky scrapers, a far cry from the homes, small shops and dirt roads of that period.

Both civilians and military personnel were buried at the site, which ran along what used to be Dorchester Street.

James McGill, a Scotland-born businessman and philanthropist best known as the founder of McGill University, was among those laid to rest at the cemetery.

His bones were later moved to the front of the Arts Building on the campus of the university that bears his name.

A Hydro-Québec worker stands by a skeleton uncovered during the installation of a new electrical line. (Hydro-Québec)

In 1854, the cemetery was turned into a park called Dufferin Square, and families were given the option of relocating the remains of their loved ones to the cemetery on Mount Royal, Burroughs said.

Not everyone took up the offer, perhaps because they couldn't afford to, he said.

After studying old city maps before undertaking the project, Burroughs said, Hydro-Québec was aware it would be digging at the site of a burial ground.

André Burroughs, an archeologist with Hydro-Québec, stands on René Lévesque Boulevard, where the old cemetery was located. (Benjamin Shingler/CBC)

But finding the skeletons — some of which were close to the surface — was a profound experience for the archeologist.

"We always talk about clay pipes and bottles being found, but when you have skeletons it's different," he said.

The skeletons have been excavated and are being analyzed by a team of archeologists hired by Hydro-Québec, Burroughs said.

Old cemeteries have been discovered under Montreal's streets before, including during construction at Place du Canada in 2012.

Last summer, the remains of an 18th-century village were found at the site of the new Turcot Interchange.