In the thirteen years since I moved back to the Okanagan, this shift in tourism has continued to the point where nature- and wine-loving visitors make up a significant part of the annual tourist population, although sun-lovers still crowd the beaches in July and August.
To paraphrase James Thurber, “I don’t know much about wine, but I know what I like.” I do, however, know a bit about natural history, and I hope that this book will allow visitors who come for wine or wildlife—or even some hot sunshine—to explore some of the Okanagan’s roads with fresh eyes for its natural treasury and to come away with a richer sense of what makes this valley one of the best places on Earth.
The Natural Okanagan
Although the Okanagan’s reputation for fine weather may be enough to bring visitors from the rain-soaked coast of British Columbia or blizzard-bound Alberta, one natural feature of the valley stands out as an obvious attraction: its diversity. Few places in Canada—or even North America—can boast its combinations of desert sands and deep lakes, towering rock cliffs and rich benchlands, and cold mountain forests and hot grasslands. Freezing winds carve back the needles on stunted firs at tree line, while only a few kilometres away a rattlesnake slides around yellow cactus flowers, hunting for pocket mice. Cattail marshes line river oxbows only a few metres from sagebrush that sends roots deep into dry soils in a constant quest for water.
This wide array of habitats is not only refreshing for the hiker or biker but a real boon to wildlife. The presence of permanent water in such an arid landscape greatly boosts the numbers and varieties of animals able to live in the area. And the statistics are impressive. About 200 species of birds nest in the Okanagan Valley, more than anywhere else in Canada. In fact, few places in North America could boast such an impressive list in such a small area—arctic birds on the mountaintops, boreal forest birds in the spruce, coastal forest birds in the cedars, and southwestern desert birds in the sagebrush. No wonder birders come from all over the continent to the Okanagan to add to their life lists. Every May teams of birders from all over British Columbia participate in the Okanagan Big Day Challenge, competing to see how many kinds of birds they can see in one crazy day in the Okanagan. I was on the team that set the long-standing record of 174 species.
And it’s not just birds, of course. Fourteen species of bats live in the Okanagan, more than anywhere in Canada, including the spectacular spotted bat, which looks like a little flying skunk with oversize pink ears. The valley is also the British Columbia hot spot for reptiles and amphibians, featuring spadefoot toads, tiger salamanders, rubber boas, and, at least formerly, pygmy short-horned lizards. One little pond near Penticton is home to almost half the dragonfly species of British Columbia. Most other invertebrate species are not well surveyed, but the presence of northern scorpions, Jerusalem crickets, and black widow spiders certainly adds spice to a prowl through the grasslands.
Another quality of the natural environment that draws visitors to the Okanagan is rarity. Many of the Okanagan’s plants and animals are found nowhere else in Canada or at least are very difficult to find elsewhere. The canyon wren is found from southern Mexico to the rocky cliffs just south of Kelowna, and the sage thrasher from Arizona to the White Lake Basin west of Okanagan Falls; the Lyall’s mariposa lily grows only on the east slope of the Cascades from central Washington north to Osoyoos; and the list goes on.
In Canada, most of the plants and animals unique to the Okanagan are associated with habitats at low elevations—the dry grasslands on the valley benches and moist woodlands and marshes along the lakes and streams. These habitats, in turn, have been the prime landscapes settled and irrevocably altered by human settlement in the past century. The Okanagan has the biggest concentration of species at risk in the country, and almost all of these species are endangered because of that combination of rarity in Canada and habitat loss. Some estimates suggest that 80 per cent of riparian habitats—the birch woodlands along the old channels of the Okanagan River and the marshes at the head of each lake—and 50 to 70 per cent of grasslands have been lost to agriculture and urban development.
The Building of the Okanagan Valley
Two hundred million years ago, there was no Okanagan Valley. Indeed, very little land stood where British Columbia is today— just the shallow waters of the continental shelf of western North America. Then, starting about 180 million years ago, a series of continental collisions occurred. Large island masses, perhaps similar to Japan or the Philippines, slid into the west coast of North America, carried by drifting continental plates. These landmasses pushed up and overrode the sedimentary rocks on the shelf, creating much of the land area of British Columbia.
The collisions continued off and on until about 60 million years ago, when the dynamics of the colliding plates changed and the tremendous pressure that had built the mountains of British Columbia largely ceased. As the eastward pressure eased, the great piled mass of southern British Columbia slumped back to the west, allowing huge cracks to appear in the land. These cracks—called relaxation faults—are some of the large valleys of British Columbia we know today—including the Rocky Mountain Trench, the Kitimat Trench, and the Okanagan Valley.
As the Okanagan Valley opened, the sedimentary rocks laid down on the old continental shelf of North America rose to the surface after being deeply buried for more than 100 million years. They had been greatly changed—melted and recrystallized into hard metamorphic rocks such as gneiss. The high rock cliffs of the south Okanagan, including the massive wall of McIntyre Bluff north of Oliver, are almost all part of this group. The rifting process that opened the Okanagan Valley was accompanied by a great deal of volcanic activity. Many of the smaller mountains in the valley—for instance, Munson Mountain in Penticton, Giant’s Head in Summerland, Mount Boucherie near Westbank, and Knox, Dilworth, and Layer Cake mountains in Kelowna—are all made of volcanic rock from this period.
For the next 50 million years or so, nothing truly dramatic happened to the Okanagan landscape. Vast outpourings of lava blanketed the Columbia Basin to the south and the Chilcotin Plateau to the northwest; some of these flowed onto the Thompson Plateau at the north end of the Okanagan, cooling into columnar basalts. The mountains slowly eroded, as mountains always do, creating rounded plateaus on either side of the valley.
Then the ice came. About 2 million years ago, the Earth’s climate cooled as the Pleistocene Epoch began. More snow fell each winter, and the summer melt decreased. Snow accumulated rapidly in the mountains of British Columbia, forming glaciers that flowed out of the Coast, Columbia, and Rocky mountains and filled the valleys. The glacier flowing south through the Okanagan Valley grew until it overtopped the plateau on either side and joined other river glaciers to form a vast ice sheet almost 2 kilometres thick. Covering all but the highest peaks in the province, this ice sheet flowed inexorably west to the sea and south over the Okanagan and other valleys to melt on the Columbia Plateau in what is now Washington State. The Pleistocene wasn’t constantly cold; it contained a half-dozen or more long periods within it when the world was warmer than it is today. The glaciers shrank and advanced with each climatic cycle; the latest major advance began about 30,000 years ago and reached its maximum extent about 15,000 years ago. Shortly after this peak, the climate warmed again, and the ice quickly melted back and was more or less gone by 12,000 years ago.
The ice sheet melted from the top down as well as from its leading edges, so the first areas free of ice were the mountaintops and plateaus, and the last remnants of the Pleistocene were huge masses of ice in the valley bottoms. Old rivers flowed again as the ice melted, but they often found their ancient paths blocked by valley glaciers or altered forever by the deep scouring action of the ice. In the south Okanagan, a large, lingering mass of ice created a big plug at the narrowest point of the