The “World’s Smallest Desert” in Canada Isn’t Actually a Desert at All

Just outside the tiny Yukon community of Carcross is a landscape that seems completely out of place in northern Canada. Pale sand stretches across rolling dunes beneath mountains, with patches of grass and scattered trees growing along the edges. For decades, the roughly one-square-mile area has been promoted as the "world's smallest desert." There is only one problem. Carcross Desert is not actually a desert. The sandy landscape at approximately 60.18722° N, 134.69472° W is more accurately described as an active dune system. It receives too much precipitation to qualify as a true desert under commonly used climate definitions, and its unusual appearance has almost nothing to do with the process that creates major deserts such as the Sahara. Its origins go back to the end of the last ice age. About 10,000 years ago, glaciers covered much of the region surrounding present-day Carcross. As those glaciers retreated, they left behind enormous lakes filled with meltwater. One of those was ancient Lake Watson. Sand and silt accumulated across the bottom of the lake. When the glaciers disappeared and water levels dropped, those sediments were exposed, leaving huge quantities of loose material behind. That ancient lakebed became the foundation for the dunes visible today. The process did not stop thousands of years ago. The Yukon Geological Survey describes the Carcross Dunes as an active dune field. Sand continues to arrive from the Watson River valley and Bennett Lake. Each spring, Bennett Lake reaches relatively low water levels, exposing broad sandy areas along its shoreline. Strong prevailing winds then pick up some of that loose material and carry it inland. Over time, the wind piles the sand into dunes. That continuing supply is important because without it, vegetation would gradually stabilize much more of the sandy landscape. In fact, parts of the Carcross dune system are already covered by grasses, shrubs and trees. The result is a strange mixture of environments. One moment a visitor can be walking across open sand that resembles a miniature desert. A short distance away, spruce and pine trees appear along the dunes. Beyond them rise snow-covered mountains and the blue water of Bennett Lake. In winter, the entire supposed desert can disappear beneath snow. That alone does not prevent a place from being a desert. Antarctica is a desert despite being covered in ice because deserts are defined primarily by how little precipitation they receive, not by whether they are hot or sandy. Carcross simply does not meet that standard. Canadian climate records for Carcross show average annual precipitation of roughly 280 millimeters when rain and melted snow are combined. Some definitions use approximately 250 millimeters of annual precipitation as a rough boundary for desert climates, although temperature, evaporation and seasonal patterns also matter. The Yukon government itself makes the distinction clear. Its information about the site says that although the area is affectionately called Carcross Desert, the dunes are not dry enough to be a true desert. The "world's smallest desert" label is therefore better understood as a nickname than a scientific record. That does not make the place any less unusual. The entire visible dune system covers only a few square kilometers, yet it supports plants and insects adapted specifically to shifting sand. One of the most remarkable is Baikal sedge, a grass-like plant that thrives in active and partially stabilized dunes. Its name hints at just how unusual its presence in the Yukon is. Other populations occur thousands of kilometers away in parts of central Asia near Lake Baikal. In North America, the species has an extremely limited distribution concentrated largely in southwestern Yukon and part of Alaska. The Carcross Dunes contain an important population. Federal researchers have estimated that roughly 200,000 Baikal sedge shoots occupy about 210 hectares of the Carcross dune system. The plant survives conditions that can be difficult for larger vegetation because blowing sand repeatedly buries and exposes the surface. Other specialized plants and insects also occupy the dunes. That ecological value has created an unusual conflict with the site's popularity. Because the dunes sit immediately beside the South Klondike Highway and only a short drive from Whitehorse, they are extremely easy to reach. Visitors walk the dunes, hike trails and photograph the landscape. Sandboarding has also become popular. Motorized recreational vehicles have caused greater concern. Federal conservation assessments have identified recreational use, particularly all-terrain vehicles, as a threat to Baikal sedge habitat. Heavy traffic can destroy vegetation that helps support the dune ecosystem. The dunes are therefore not simply a giant sandbox. They are a living and changing landscape. Even their size has been changing. Yukon conservation material has noted that aerial photographs show a reduction in dune area over several decades as vegetation moves into previously open sand. Wind continues pushing new sand inland while plants gradually stabilize other sections. That constant competition between moving sand and vegetation is what keeps the landscape looking the way it does. The nearby community has an equally interesting setting. Carcross sits between Bennett Lake and Nares Lake, approximately 74 kilometers south of Whitehorse. Its original name was Caribou Crossing, referring to woodland caribou that historically traveled through the narrow area between the lakes. During the Klondike Gold Rush, Carcross became an important transportation point along the route toward the Yukon interior. The White Pass and Yukon Route railway, completed around the turn of the 20th century, still passes through the community. Today, however, one of the first things many travelers notice north of town is the sand. Against the surrounding mountains, forests and cold northern lakes, the dunes can look almost impossible. They are real sand dunes, and they are genuinely unusual. They just are not a tiny piece of the Sahara somehow stranded in Canada. What looks like the world's smallest desert is actually the surviving result of an Ice Age lake, thousands of years of wind, seasonal changes in Bennett Lake and a continuing supply of sand that still reshapes the Yukon landscape today.