Great Divide Trail

The Great Divide Trail is a hiking trail in the Canadian Rockies, made up of several trails connected by roads and wilderness routes. It closely follows the Great Divide between Alberta and British Columbia, crossing it more than 30 times. Its southern terminus is at the Canada–US border, and its northern terminus is at Kakwa Lake, north of Jasper National Park. The trail is long and ranges in elevation from to. Although the idea and first trail work goes back to the 1960s, the project went dormant for decades until the early 2000s.
The GDT is most often hiked from early July until early September, when it is nearly free of snow. It generally takes between five and ten weeks, about seven at an average pace. Although there are popular sections that see thousands of hikers each year, fewer than 100 people thru-hike the entire GDT annually.

History

The first record of the Great Divide Trail appears in 1966, when the Girl Guides of Canada proposed the idea of a trail running the length of the BC–Alberta border through the Rocky Mountains. In 1970, Jim Thorsell published the Provisional Trail Guide and Map for the Proposed Great Divide Trail. Thorsell's route comprised roughly the middle 50% of the modern trail, from Banff's southern boundary at Palliser Pass to Berg Lake. Parks Canada approved the project, with the objective of completing the GDT in five years.
Outside of the national parks, the route south of Palliser Pass was originally mapped in 1974 by six University of Calgary students with support from the Alberta Wilderness Association and the Federal Opportunities for Youth Program. Mary Jane Cox, Jenny Feick, Chris Hart, Dave Higgins, Cliff White, and Dave Zevick surveyed an estimated along the proposed GDT route through public lands. Despite initially low enthusiasm from the Alberta and BC governments, whose representatives cited a lack of interest in the trail and a priority on resource development, the group founded the Great Divide Trail Association in April 1976 and began trail construction that summer.
Parks Canada continued to study the idea, but the agency was concerned about overuse and never moved forward with it. By the mid-1980s, with funding from the Alberta government, crews had built 90 km of trail from North Fork Pass to Fording River Pass. When support from the province of Alberta ended, and logging and off-road vehicle use destroyed trails, work ceased, and the GDTA became inactive.
In 2000, Dustin Lynx revived the GDT by releasing his guidebook Hiking Canada's Great Divide Trail. By 2004, a group known as the Friends of the Great Divide Trail began to work on the GDT once again, particularly in the unprotected Alberta Crown lands between Crowsnest Pass and Banff National Park. In 2013, the Friends of the Great Divide Trail re-activated the GDTA as a nonprofit corporation headquartered in Calgary. Since then, the association has conducted annual maintenance and trail-building throughout the length of the GDT.
In 2023–2024, the GDTA became the official trail manager of the GDT on Alberta public lands. The association also reached 600 members.

Geology

The Great Divide Trail is entirely within the Continental Ranges of the Canadian Rocky Mountains and traverses all but their southernmost extent, which stretches well into Montana. These ranges are bounded on the east by the Interior Plains and on the west by the Rocky Mountain Trench. North of Jarvis Creek, just beyond the GDT's northern terminus, the Continental Ranges end and the Hart Ranges begin.
The GDT passes through mountains that are largely composed of sedimentary rock. Limestone, shale, and quartzite are very common along the trail and date from the late Neoproterozoic to the Cretaceous, far younger than the granite and gneiss commonly found in the American Rockies. The exception is in Waterton Lakes National Park, which has some of the oldest rock in the Canadian Rockies, from the Purcell Supergroup.
The Canadian Rockies did not experience additional volcanic uplift, and so the GDT travels through generally lower-elevation valleys and passes than the CDT in the American Rockies. However, the deeper valleys and steep mountain walls caused by heavy glaciation give the Canadian Rockies, particularly the large mountains along the divide, comparable or even greater prominence than the highest American peaks.

Points of interest

There are unique rocks visible from or near the GDT in Waterton Lakes National Park in the Clark Range. Among the typical layers of limestone and dolomite, there are red and green siltstones called argillite, black bands of igneous Purcell Sill, and stromatolites: fossils of cyanobacteria colonies.
Upper Waterton Lake, at the southern terminus, is the deepest lake in the Canadian Rockies at. It is a finger lake; glaciers carved its present deep, steep-sided shape out of an ancestral river valley, deposited a dam of debris at the northern end of the valley while retreating, and filled the valley with meltwater.
Mount Assiniboine on the divide between Banff National Park and Mount Assiniboine Park is an example of a glacial horn, or pyramidal peak. It was shaped by cirque glaciers that eroded its flat, steep sides, and is frequently referred to as the "Matterhorn of the Rockies". With an elevation of, it is one of the ten tallest peaks in the Canadian Rockies.
The Burgess Shale of the Waputik Mountains in Yoho National Park is a formation containing large numbers of exceptionally well-preserved fossils dating to over 500 mya. From his discovery of the fossils in 1909 until 1924, Charles Walcott collected 65,000 specimens. The vast diversity of soft-bodied organisms preserved in the formation has been highly informative to paleontology and paleoclimatology.
There are extensive karst systems on or just off the GDT through the Palliser Formation, in and around southern Jasper National Park. Caves, sinkholes, and slot canyons are formed by slightly acidic surface water dissolving passages in the limestone layers. Examples include caves at the head of Cataract Valley and at the outlet of Medicine Lake, down the Watchtower Access Trail. During most years, the entire flow of the Maligne River drains through underground passages from the lake and emerges in Maligne Canyon, away.
Maligne Canyon itself is an accessible example of a karst slot canyon just off the GDT, at the north end of Section E. It is up to deep and just across at some points. Other examples directly on the GDT include Turbine Canyon in Peter Lougheed Provincial Park, near the south end of Section C; Mistaya Canyon, cut into the Eldon Formation at the north end of Section D; and just north of the Owen Creek trailhead in section E.
Maligne Lake is the longest natural lake in the Canadian Rockies, at. It was formed after the Last Glacial Maximum,, when the glaciers rapidly receded, then briefly re-advanced to deposit a large terminal moraine, before retreating to the large mountains beyond Coronet Creek. That moraine now forms the north shore of Maligne Lake.
Mount Robson is the highest peak in the Canadian Rockies and the most prominent anywhere in the Rocky Mountains. Its height is due to its location at the base of a syncline. While nearby mountains are tilted by tectonic forces deforming the rocks, Robson's layers remained relatively horizontal and thus more stable and resistant to erosion. While the highest mountains are usually directly on the continental divide, Mount Robson is several kilometres southwest of the divide, completely within British Columbia. The junction between the North Boundary Trail and the Berg Lake Trail is at the northern base of the Robson Massif.

Climate

The Continental Ranges of the Canadian Rockies that the GDT passes through have a continental climate, with a wide range of temperatures between seasons and moderate precipitation; there is generally more precipitation on the west side of the divide. The trail is mostly covered in snow until June, which can linger well into July, particularly on the northeast sides of passes, due to less direct sunlight and deeper snow drifts caused by the prevailing westerly winds. Of the months that the GDT is typically hiked, June is the wettest, with average precipitation decreasing through the summer and fall. July is the warmest month, with typical daily highs between and. By September, precipitation often falls as snow at higher elevations, and overnight lows in the valleys are near freezing.
Mountain weather is highly variable, and the GDT is no exception, as the trail goes up and down in elevation, from one valley to another, and from one hour to the next. The lapse rate is a drop in air temperature of at least 0.7 °C for every increase in elevation. Because the prevailing winds are perpendicular to the mountain ranges, winds below treeline are often lighter and shifting. However, the valleys that are aligned southwest-northeast tend to have strong, steady winds. In the afternoons of hot July and August days, there is a greater chance of sudden thunderstorms that may be accompanied by hail.

Route

While portions of the GDT are recognized and supported by the province of Alberta, the GDTA continues to work towards a formal designation, including by Parks Canada, for the long-term protection of the trail. According to the GDTA:

The GDT is officially signed in portions of Sections A, B, D, and G, but elsewhere the GDT is not officially signed. Much of the trail within national and provincial parks is well marked but not identified as the GDT. The route is actually made up of several separate trail systems joined together by ATV tracks, roads, and wilderness routes. The GDT varies from being a well-developed, signed trail to an unmarked, cross-country wilderness route where navigation skills are required.

Since the trail follows the Canadian Rocky Mountains, it runs generally northwest–southeast, with the northern terminus being further north—equivalent to 5° of latitude—and west of the southern terminus. The GDT passes through five national parks, nine provincial parks, four wilderness areas, and four forest districts. The trail is commonly broken up into seven sections, A–G, based on access and resupply.