One of only four UNESCO biosphere reserves in the province, Frontenac Arch is a geological wonder containing islands that were once mountaintops and more rare species than anywhere else in the country. Today, a steadfast coalition of conservation organizations, landowners and others, including Ontario Nature, are trying to save this unusual place

by Alec Ross

It’s a sunny morning in April, and I’m hiking with my son and daughter beside Landon Bay, a fjord-like cove on the St. Lawrence River 32 kilometres east of Kingston. We stroll among bare-branched silver maples whose fallen leaves crunch underfoot. Little signs identify some of the other trees: red oak, basswood, shagbark hickory, blue beech, white ash, eastern white pine. A chittering red squirrel scurries up a leaning cedar. The trail weaves upward among granite boulders, and soon we reach the summit of the hill-mountain.

Treasure Islands

Although small at 405 hectares, St. Lawrence Islands National Park contains a surprisingly high number of rare species and geologists have long been fascinated with the area.

Located in the St. Lawrence River in the heart of the Thousand Islands, the rounded islands that make up the park are the peaks of an ancient mountain range, exposed after the glaciers retreated.

Rich in biodiversity, the park is home to more than 30 species designated federally as being at risk, including the endangered king rail and eastern prairie fringed orchid. Three of Ontario’s at-risk turtle species are also found there. As part of the Frontenac Arch, the more than 20 island and mainland properties that make up the park form a key part of the contiguous ecosystem that extends from the Canadian Shield to the Adirondack Mountains in New York State.

Jim MacInnis

Below us is Landon Bay, dark blue and ringed by cattail marshes. To the south, white haze shrouds the St. Lawrence River and some of the 1,800 or so islands and islets that dot the waterway between Gananoque, five kilometres west, and Brockville, 45 kilometres northeast. Trees block our westward view, but to the north and east is an undulating landscape of conifers, naked hardwoods and dark granite cliffs. As we contemplate this vista, two hitherto invisible turkey vultures on a ledge below us suddenly lurch skyward, flapping clumsily, so close that we can see their wrinkled red-skinned heads and hooked beaks.

“Awesome!” bellows my son, who has never seen such a big bird at such close range. “This must be a pretty special space, Dad.”

Noah is right. Little does my six-year-old know that the eastern Ontario woodland surrounding us, which nearby St. Lawrence Islands National Park recently acquired, contains a diversity of plant and animal species that is among the richest in Canada. This extraordinary abundance is rooted in Landon Bay’s location within the Frontenac Arch, an 80-kilometre-wide bridge of the Canadian Shield that connects Algonquin Provincial Park in Ontario with the Adirondack Mountains in New York State. Where it lies beneath the St. Lawrence River between Kingston and Brockville, this strip of granite bedrock forms the Thousand Islands. When glaciers retreated 10,000 years ago, the rounded tops of a Precambrian mountain chain were left exposed. As the St. Lawrence River poured through on its way toward the Atlantic Ocean, the mountaintops became islands that today are a popular summer playground for Canadian and U.S. cottagers, boaters and tourists.

Because wildlife can follow the Frontenac Arch roughly north and south, and the St. Lawrence corridor east and west, the Thousand Islands and the arch itself contain a veritable explosion of life, from lynx to bald eagles to painted turtles, and, strikingly, almost three dozen at-risk species. So noteworthy is the Frontenac Arch that the United Nations Educational, Scientific and Cultural Organization (UNESCO) designated it as a World Biosphere Reserve in 2002. There are only three other such areas in Ontario – at Long Point, the Niagara Escarpment and the eastern coast of Georgian Bay – 13 in Canada and 507 in the world. “Most people are surprised to learn that there are more rare flora and fauna in this part of eastern Ontario than anywhere else in the country,” says Don Ross, a biologist and a former chief naturalist at St. Lawrence Islands National Park, which forms the epicenter of the arch’s species diversity. “The Frontenac Arch really is a world-class ecological treasure. The big challenge is to keep it that way.”

Ross has a point. Only a tiny fraction of the significant forests and wetland habitats of the Frontenac Arch lie within protected areas such as St. Lawrence Islands National Park, Charleston Lake and Frontenac provincial parks, and a handful of nature reserves, conservation areas and provincial Areas of Natural and Scientific Interest (ANSIs). Together, they make up a mere 5 percent of the Biosphere Reserve area.

Herein lies the problem. These areas are widely separated, and the vast majority of land between them is privately owned. Cottages, year-round residences, marinas and other businesses line the Canadian and U.S. shores of the St. Lawrence, summer homes occupy a great many of the Thousand Islands and farms occupy large tracts of inland terrain. Such development is likely to increase, and, without pre-emptive action, so will environmental troubles such as the soil and water pollution that go along with it. Consequently, the future of the species at risk that inhabit the arch depends on the willingness of the region’s people to live and prosper in ways that will not irrevocably jeopardize the existence of their non-human counterparts. That, in large measure, means creating and safeguarding as many wildlife corridors between the existing habitats as possible.

Wendy Francis, Ontario Nature’s director of conservation and science, compares the Frontenac Arch to the Niagara Escarpment and the Oak Ridges Moraine, southern Ontario’s best-known geological features. “The Frontenac Arch is of similar import,” she says. “It also merits the same sort of public profile and policy protection as the others do.”


The Frontenac Arch, located in southeastern Ontario, is a UNESCO-designated World Biosphere Reserve largely because the area is so rich in biodiversity and contains many species at risk. These species include the endangered butternut tree, eastern loggerhead shrike, Henslow’s sparrow, northern bobwhite and American ginseng.

Among the species designated as threatened are the black rat snake, golden-winged warbler, grey fox, least bittern and peregrine falcon. Species listed as being of special concern are the cerulean warbler, eastern milksnake, eastern yellow breasted chat, five-lined skink, monarch butterfly, northern ribbonsnake, red-headed woodpecker and short-eared owl.

Shannon Wilmot

Roughly the size of P.E.I., the Frontenac Arch was shaped over eons by the uplifting of the earth’s crust and subsequent advances and retreats of ice-age glaciers. Hence the arch’s characteristic Canadian Shield topography: thin soil, rounded granite slopes, knobs and outcrops separated by shallow, steep-sided valleys with deeper soils, the erstwhile bottoms of postglacial lakes. Overall, about 40 percent of the arch region is forested, while 30 percent of it is lakes, rivers, streams and wetlands. Because of all the hills, rocks and water, agricultural land occupies only 15 percent of the arch; the rest of it consists of small towns, villages and other scattered settlements. The preponderance of relatively untrammeled natural habitats and micro-niche ecosystems gives the species that inhabit them a fighting chance to exist.

Denizens of the arch are a remarkably diverse lot. Canadian Shield species such as white-tailed deer, grey and red squirrel, and pileated and red-headed woodpeckers occur naturally, but, as a direct consequence of the crossroads phenomenon, several species also reach the limits of their normal range here. For example, the lynx, snowshoe hare and northern flying squirrel, creatures typical of northern boreal forests, reach their southern limits in the arch. Species common in southern regions such as cardinal, mourning dove, wood thrush and even opossum reach the boundaries of their northern range. Almost the entire Canadian population of pitch pine, a species characteristic of the pine barrens of New Jersey, is found in the Frontenac Arch. Red spruce and wire birch from the Atlantic coast reach their western limit here, while buttonbush, a shrub common in Florida swamplands, and the five-lined skink, Ontario’s only lizard, extend no further east.