The Alberta portion of the #3 Crowsnest Highway runs for approximately 323 km (201 mi) from the British Columbia border to Medicine Hat, where it connects with the #1 Trans-Canada main route.
It begins in Crowsnest Pass paralleling the Canadian Pacific Railway, first meeting Highway 40 (the Forestry Trunk Road) at Coleman, then running 26 km (16 mi) east through Blairmore, Frank, Bellevue, and Burmis (from west to east), recently amalgamated and collectively known as the Town of Crowsnest Pass, and barely clearing the eastern ranges of the Rockies to the southern terminus of Highway 22, better known as the Cowboy Trail. The Bar U Ranch National Historic site and the towns of Okotoks, High River, and Black Diamond are an hour to the north.
Highway 6 heads south near Pincher Creek and is the main route to Waterton Lakes National Park on the border with the United States. Approximately 50 km (31 mi) east of Pincher Creek, the highway becomes divided and has an interchange with Highway 2 (north to Head-Smashed-In Buffalo Jump) Calgary and then east for 5 km (3 mi) into the town of Fort Macleod, after which Highway 2 south goes to Standoff, Cardston, and the United States border at Carway.
From the Highway 2 junction, the #3 Crowsnest Highway its “twinned” and Highway 3 east of Fort Macleod crosses the Oldman River near Monarch. Highway 3 passes Lethbridge’s west side with interchanges for Westview Drive W (to the south) and University Dr W (to the south) and Highway 25, heading north to Picture Butte.
The Crowsnest Highway now crosses the Old Man River, with the famous High Level Bridge for the railway to the south, Fort Whoop-Up in the valley below the bridge, and the University of Lethbridge campus buildings clinging to the western coulee slopes dropping into the deep river valley.
After Highway 3 crosses the Oldman River into Lethbridge, the freeway segment ends at Mayor Magrath Drive, the junction which marks the northern terminus of Highway 5 (eastern access to Waterton Lakes National Park). The highway then has a junction with Highway 4 (to Milk River and the US border at Sweetgrass, Montana and I-15 heading south).
After passing the eastern limit of Lethbridge the highway passes through Coaldale and Taber. At Taber, Highway 36 runs concurrently with Highway 3 for 3 km (2 mi). Highway 36 is a north-south road, running north to Brooks on the main Trans-Canada, and south to Warner, Milk River , Sweetgrass, Montana and I-15 in the US.
The Crowsnest Highway reduces to a two-lane undivided road and passes through a number of small towns including Grassy Lake, and Bow Island before joining the Trans-Canada Highway at Medicine Hat.