Alberta Highway 21A

The southern section of Highway 21A was a 33 km (21 mi) highway which started at Highway 9 in the Village of Beiseker and traveled north for 13 km (8 mi) to the Village of Acme and then turned east for 20 km (12 mi) to Highway 21, 8 km (5 mi) northeast of the Village of Carbon.^[1] It was established in 1958/59 when Highway 21 was realigned from Beiseker to Highway 1 (Trans-Canada Highway) east of Strathmore.^[3][4] Highway 21A was renumbered to Highway 26 in 1962/63,^[5][6] and in 1972/73 the north–south section became Highway 806 while the east–west section became Highway 575.^[7][8]

The northern section of Highway 21A was a 5 km (3 mi) highway that connected Highway 21 with Highway 12 near the Hamlet of Nevis.^[2] In the early-1990s, Highway 11 was extended east from Highway 815 near Joffre to Highway 21; when construction was completed, Highway 21A became part of Highway 11.^[9][10]