Highway 3 (officially named the Crowsnest Highway) is a highway that traverses southern Alberta, Canada, running from the Crowsnest Pass through Lethbridge to the Trans-Canada Highway in Medicine Hat. Together with British Columbia Highway 3 which begins in Hope, British Columbia, it forms an interprovincial route that serves as an alternate to the Trans-Canada from the Lower Mainland to the Canadian Prairies.
Highway 3 begins as a two-lane continuation of BC Highway 3 in the Canadian Rockies at Crowsnest Pass, winding through the foothills to a junction with Highway 2 west of Fort Macleod. Briefly concurrent with Highway 2, it becomes a divided highway and part of Alberta's "Export Highway", a segment of the CANAMEX Corridor that stretches from Alaska to Mexico. In Lethbridge, it is an expressway named Crowsnest Trail that crosses the Oldman River and meets the northern termini of Highways 4 and 5; the former is a major route that assumes the designation of the Export Highway, connecting to Interstate 15 in Montana, while the latter branches southwest to Magrath and Cardston. East of Lethbridge, it bisects Coaldale and Taber before reverting to a two-lane highway that ends at Highway 1 in Medicine Hat.
For its entire length, Highway 3 follows the alignment of the Canadian Pacific Railway. It was first a rough dirt road known as the Red Trail plotted in the early 1900s. Later numbered as Highway No. 3, it was designated as a southern branch of the former Trans-Canada Highway by the 1920s and improved to gravel then eventually paved, widened with shoulders, and upgraded to an expressway in sections. The Trans-Canada was officially routed through Calgary in the 1960s, but Highway 3 remained an important alternate route to the west coast and was incorporated into the National Highway System in 1988. Twinning of the first segment between Lethbridge and Coaldale had been completed by the mid-1960s, and it was officially named the Crowsnest Highway in the late 1970s. A major expressway realignment along Crowsnest Trail in central Lethbridge was completed in the 1980s, and twinning of the Fort Macleod–Lethbridge segment was completed in the mid-1990s.
The Ministry of Transportation and Economic Corridors has long-term plans to upgrade the entire route to a freeway by twinning its undivided sections and removing intersections. Unfunded plans have been drafted for a northern Lethbridge bypass, realigning Highways 3 and 4 to the north and east of the city respectively, while a Fort Macleod bypass will realign Highway 3 to the south connecting to a newly extended Highway 2. A $150 million project to twin a section from Taber to Burdett will be completed in summer 2026, with additional twinning near Medicine Hat in late planning stages.
Route description Highway 3 was designated as one of the original core routes of the National Highway System in 1988, an interprovincial route connecting large population centres. Most of the road is an undivided, two-lane highway, with a speed limit of outside of rural areas. From Fort Macleod to West Lethbridge and from Coaldale to Taber, it is a divided highway with a speed limit of . Highway 3 is a divided expressway between Fort Macleod and Lethbridge that forms a portion of Alberta's Export Highway, a segment of the CANAMEX Corridor that facilitates the movement of goods between Alaska and Mexico. The Fort Macleod–Lethbridge segment also comprises the westernmost portion of the Red Coat Trail, a historic route advertised as that which was travelled by the North-West Mounted Police in the late 19th century in their quest to bring order and peace to the region.
Crowsnest Pass and foothills
British Columbia Highway 3 is a two-lane, undivided highway that becomes Alberta Highway 3 at the border in mountainous terrain, paralleling a branch of the Canadian Pacific Railway. It first crosses over to the south side of the railway and passes through the centre of Island Lake on a causeway, part of which is natural terrain. It curves through communities of the Municipality of Crowsnest Pass on the south side of Crowsnest Lake, crossing the Crowsnest River and reaching Highway 40 at Coleman. It continues alongside the railway through Blairmore, again crossing the Crowsnest River and bisecting the community of Frank and the rubble of the Frank Slide, a landslide in which approximately 110 million tonnes of limestone broke away from Turtle Mountain and killed more than 70 people in 1903. The highway, the Crowsnest River, and the railway meander east into the Municipal District of Pincher Creek No. 9 and Burmis from which Highway 507 splits south to Beaver Mines and forms an alternate route from the west into Pincher Creek. Highway 3 curves northeast to the hamlet of Lundbreck which it bypasses, and from which Highway 22 begins and runs north. The first of four former alignments of Highway 3 (all of which are now designated as Highway 3A) passes through Lundbreck, splitting from Highway 3 prior to the hamlet and rejoining it after .
East of Lundbreck and Cowley, the highway crosses Castle River to Highways 6 and 785 north of Pincher Creek. It briefly parallels the creek for which the town was named before crossing it and reaching Brocket, and Highway 786 which meets Highway 507 southeast of Pincher Creek. Highway 3 follows the Oldman River to Fort Macleod, approximately east of Brocket. Just prior to Fort Macleod, the highway enters the Municipal District of Willow Creek No. 26 and Highway 810 splits south to the communities of Ardenville and Glenwood after which Highway 3 widens to a divided highway. It meets Highway 2 at a trumpet interchange, and diverges into a one-way road pair through Fort Macleod at a reduced speed limit of , concurrent with Highway 2. Highway 811 turns north from Highway 3 in central Fort Macleod to cross the Oldman River on a historic alignment of Highway 2. At the Fort Macleod Health Centre, Highways 2 and 3 curve southeast to leave the town as the one-way roads rejoin into a divided highway. The concurrency ends as Highway 2 splits south as a two-lane highway to Cardston and the United States border at Carway. Highway 3 bends back to the northeast, now designated as the Red Coat Trail and carrying CANAMEX traffic destined for the primary border crossing on Highway 4 at Coutts.
The divided highway continues northeast from Fort Macleod with a speed limit of , paralleling the Oldman River. It curves east to bypass Monarch to the south and crosses the river, entering Lethbridge County. Highway 3 formerly passed through Monarch until the 1990s construction of the bypass; that route is now designated as Highway 3A and meets Highway 23 east of the town which then joins Highway 3 north of the confluence of the Oldman and Belly Rivers. After curving southeast, Highway 509 splits southwest to Stand Off. Highway 3 intersects 51 Avenue, the main access for the town of Coalhurst. Westview Drive splits into West Lethbridge at a partial interchange and for less than one kilometre it forms the third route designated as Highway 3A. Highway 3 continues east, entering the city of Lethbridge as a freeway and meeting Highway 25/University Drive at a partial cloverleaf interchange. Highway 25 runs north to Picture Butte, while University Drive connects to the University of Lethbridge and is the main thoroughfare of West Lethbridge.
Lethbridge and southeastern Alberta
+ Traffic volumes (2025) Location Volume BC border 5,810 Ft. Macleod 8,500 Lethbridge 30,240 Taber 11,210 Medicine Hat 12,650 Highway 3 is named Crowsnest Trail in Lethbridge. Immediately east of Highway 25 it descends into the Oldman River valley, entering city limits near a trumpet interchange at Bridge Drive. It then crosses the river as the speed limit reduces to . The highway interchanges with 5 Avenue N and Scenic Drive in north Lethbridge. It passes north of Park Place Mall to a diamond interchange at Stafford Drive. The freeway passes over 13 Street, to which access is provided only from the westbound direction. The freeway section ends at an interchange with Mayor Magrath Drive, the northern terminus of Highway 5. Crowsnest Trail continues east as an expressway past several at-grade intersections to 43 Street, a busy thoroughfare on the eastern city limit of Lethbridge and the northern end of Highway 4. The Red Coat Trail and CANAMEX Corridor follow Highway 4 south out of Lethbridge, while a divided Highway 3 continues east to Coaldale with a speed limit of , unlike the section west of Lethbridge which has a posted limit of 110 km/h.
The Crowsnest Highway bisects Coaldale, intersecting Highway 845 in the centre of town. The speed limit returns to 110 km/h as the divided highway continues northeast, then due east into the Municipal District of Taber. It bypasses Barnwell to the south, while the final former alignment designated as Highway 3A bisects the town. At the west end of the town of Taber, Highway 864 splits north to Vauxhall. Highway 36 then splits south to its southern end at Warner, while Highway 3 continues through the centre of Taber concurrent with Highway 36 until a signalized intersection at the east end of town where the latter splits north to Brooks.
East of Taber, the divided highway ends and the two-lane road continues east across the prairies of southern Alberta past the hamlets of Purple Springs and Grassy Lake into County of Forty Mile No. 8. After Burdett it crosses Highway 879 to the town of Bow Island. Before Seven Persons, the highway enters Cypress County and intersects Highway 887 as it veers northeast to enter the city of Medicine Hat from the southwest. It becomes a divided expressway called Gershaw Drive SW that passes north of the Medicine Hat Airport. Eventually, the Crowsnest Highway ends at the Trans-Canada Highway (Highway 1); Gershaw Drive continues into downtown Medicine Hat as Highway 41A.
History Early years
Many major highways in Alberta are predated by historic railway lines for significant portions of their length, including Highways 1, 2, 4, and 12 through 16. The inception of the trail that would become Highway 3 was similar, with the 1898 completion of a main line of the Canadian Pacific Railway spurring development in the Crowsnest Pass region. The railway connected Kootenay Landing near Creston, British Columbia to Lethbridge and was the primary method of transport until a rapid increase of private automobile use in the early 20th century. In 1926, major highways in Alberta began receiving numbers; previously all routes had been identified by coloured bands tied to telephone poles. The Red Trail officially became Highway 3 in 1932.
Inception