Historical conservationist Stephen Otto mounted a victorious defence of Fort York

In September, 1994, Toronto council was poised to approve a massive development proposal that would put thousands of apartments onto a tract of industrial land snaking along the north side of Lake Shore Boulevard from Bathurst Street to Strachan Ave. That real estate, in the shadow of the Gardiner Expressway, had long been home to a brewery and a dusty concrete plant, and tucked in behind was Fort York.

The application surfaced at a pivotal moment, when council was approving plans for the redevelopment of the railway lands.

With the Lake Shore plans barrelling forward, an upstart group called Friends of Fort York (FoFY) surfaced with sharp criticisms. “What is proposed,” said the group’s co-founder, heritage conservation expert Stephen A. Otto, “is on a scale that overpowers the fort and is inappropriate for the site.” A wall of condos would block access to Fort York, he added.

But Mr. Otto and Friends weren’t NIMBYs; quite the opposite, in fact. They were aiming to give Fort York breathing space so the garrison could become physically and socially integrated into the city that existed because of it.

In the spring of 1995, the city and the builders returned with a scaled-down plan that called for the development of Fort York Boulevard and public space along the fort’s southern ramparts, as well as a series of north-south view corridors and parks linking the fort precinct to Lake Shore Boulevard.

“What we like,” Mr. Otto said to a reporter about the revised design, “is that it gives the fort the accessibility, the visibility and the dignity we think is appropriate. It’s a national historic site. It should be treated in more than a passing way.”

It’s safe to say that not even the British Army defended Fort York with the determination that Mr. Otto brought to the task. “Steve always believed that Fort York was the birthplace of Toronto,” says Don Cranston, FoFY’s chair. “He felt that knowing the area provides a rootedness for all residents [of Toronto], not just the direct descendants of the original settlers.”

He applied a similar level of energy to the painstaking task of documenting, archiving and conserving Ontario’s built heritage. Colleagues and friends describe his knowledge of the city’s history and its built form as encyclopedic, while Mr. Otto’s legacy of stewardship in Toronto is without parallel.

After a long battle with lymphoma, he died at his Toronto home on April 22, just five days shy of the 205th anniversary of the sacking of Fort York by American forces. He was 78.

Mr. Otto was born in Toronto on Feb. 5, 1940, the eldest son of George and Audrey Otto. Though he grew up in North Toronto, Mr. Otto attended the University of Toronto Schools in the early 1950s. His friend, lawyer Michael Vaughan, described him as “a star,” a teen known for his brains, prowess as a competitive swimmer and figure skater, and his dancing ability. “He moved beautifully in the water and on the dance floor,” says Mr. Vaughan, who adds that he didn’t recall Mr. Otto showing any early interest in history or architecture.

Mr. Otto studied commerce at U of T and history at Cambridge University. After spending five years in entry-level jobs at Dominion Stores, he got his MBA from Harvard, returning to Toronto to work at Laura Secord.

In 1972, he got himself appointed to the Ontario Heritage Foundation, a position that set him up for a highly influential career in conservation policy. He joined the Ontario government in 1975, and soon became the province’s top heritage official, known as an imperious but highly effective bureaucrat.

Mr. Otto drafted the Ontario Heritage Act, which established various heritage protection bodies. He also played a key role advancing policies overseeing archeology, conservation, museums, public commemoration and heritage education, as well as the preservation of historic sites such as Sainte-Marie Among the Hurons, in Midland; old Fort William, in Thunder Bay; and the Gooderham and Worts Distillery, in Toronto.

Mr. Otto went on to a career as a consulting historian, author, editor and advocate. He was known for his extensive contacts, strategic savvy and tenacity, as well as a wry sense of humour. “This was a guy who had a Rolodex as big as Brian Mulroney’s,” says Scott James, the former City of Toronto archivist. Yet Mr. Otto was also generous to the causes he believed in, and never balked at sharing his extensive knowledge with other heritage researchers.

As those in the field know, the heritage preservation business can be a minefield of conflicting interests and interpretations. In that environment, Mr. Otto understood the importance of amassing evidence.

Indeed, a crucial element of Mr. Otto’s legacy involved ferreting out long-misplaced documents that, once preserved and catalogued, could be used to prove the heritage value of older buildings, many of which were under constant threat of demolition. He was intimately involved, for example, in unearthing hard-to-find evidence of the location of Toronto’s first Parliament site before archaeologists succeeded in digging up artefacts from Upper Canada’s original legislature under a car wash parking lot.

In the early 2000s, Mr. Otto and Rollo Myers, another energetic local history advocate, exhumed documents proving the existence of the so-called Walks and Gardens Trust, a formal legal structure created in the 19th century to finance the development of parkland near the waterfront. Amid the rush of industrial activity in the early 20th century, city officials somehow managed to bury the trust, and with it their legal obligations to develop a space that, if built, would have transformed downtown.

In one episode, he salvaged a large tranche of rare 19th-century architectural records from numerous firms, the “Horwood Collection,” that had been mouldering in a Mimico garage at the end of a narrow driveway. Mr. Otto and two of his office staff hauled out the boxes of damp documents and drove them to the Ontario Archives.

He was acutely aware of the fact that collectors, including public institutions, were all too happy to make off with valuable historical documents and also how institutions would hoard them. With the Horwood Collection, he commissioned an inventory of its hundreds of items and made that list public in 1979, prompting a storm of public interest and spurring archive officials to prepare the documents for the public. Mr. Otto, always media savvy, mentioned drawings of a former Globe and Mail building to one of the paper’s reporters.

More recently, Mr. Otto made common cause with Spacing magazine, and was a fixture at its launch parties, mingling easily with urban-minded millennials less than half his age. He also teamed up with a computer programmer and fellow antique map enthusiast named Nathan Ng to create a website with a comprehensive digitized collection of historical Toronto maps.

But Mr. Otto’s attention rarely strayed from Fort York. In the run-up to the bicentennial of the War of 1812, he donated $250,000 to the Fort York Foundation to support the development of a visitor’s centre, which garnered $4-million in funding from the federal government and opened in 2014. The highly regarded museum, designed by Patkau Architects Inc. and Kearns Mancini Architects Inc., added a 21st-century presence to the site. Mr. Otto welcomed its thoughtful modernist architecture, which relates to the historic shoreline of the city, and he continued to advocate and raise funds for the completion of the building and landscape.

A generation after those early FoFY skirmishes, there’s little doubt about the impact of Mr. Otto’s advocacy. The fort, long starved of oxygen, is now a hub of activity and festivals, and its grounds serve as part of a network of open spaces connecting the fort to the lake shore and eventually up to King Street West with the completion of a long-delayed pedestrian bridge.

The latest, the Bentway, wends under the Gardiner Expressway along the fort’s south edge, and exists only because of those mid-1990s efforts by Mr. Otto and his gang of urban guerillas to resist encroachment and instead incorporate Fort York into the life of the city. As Mr. Cranston says, he had the instincts of a great urban planner.

During the final months of his life, Mr. Otto and a circle of devoted friends were pushing to complete a final book project, one that had been on his mind for years, according to long-time collaborator Lynne DiStefano, a professor of architectural conservation.

It grew from something he had embarked on decades earlier, when he published an updated and re-edited 1986 edition of Toronto: No Mean City, architect Eric Arthur’s 1964 cri de coeur about the loss of much of the 19th-century architecture that graced the downtown. He updated the book again in 2003.

After that, Prof. DiStefano says, Mr. Otto “started working on a book to help people understand the architectural history of the entire province.” He had completed four sections, assembled 400 illustrations and was working on the fifth and final part even in his final days. The book, to be published by University of Toronto Press, “is in many ways a testament to his scholarship,” she says. “It’s a gift to the people of Ontario.”

The manuscript, tentatively titled With Strong Hands: Ontario Architecture from Prehistory to 1914, will be completed by Geoffrey Simmins, a professor emeritus of art history with the University of Calgary.

Mr. Otto was named to the Order of Canada late last year. Predeceased by his parents, he leaves his younger brother, Larry, of Kamloops, B.C., as well as his two nephews, Matthew and Ian.

John Lorinc is special to The Globe and Mail