Highway 18 begins northwest of the town of
Mayerthorpe at the junction of Highway 43 at the hamlet of Green Court. It proceeds east for , crossing the terminus of
Highway 22 prior to reaching
Highway 757. It turns north for a few kilometres and bends east again until it crosses
Highway 764, then curves north again. The jog in the road skirts
Thunder Lake Provincial Park to the north. Upon reaching
Highway 763, Highway 18 turns east to the Town of
Barrhead where it meets
Highway 33. The two highways run
concurrently to the north for approximately until a T–intersection north of town. Highway 18 then turns east from this intersection while Highway 33 turns west.
Highway 769 branches to the north towards
Neerlandia, east of this intersection. Highway 18 then crosses
Highways 776 and
777 before it reaches
Westlock at
Highway 44, some from the starting point. It continues east, crossing
Highway 2 at
Clyde at an intersection known as "Clyde Corner". The highway goes through Thorhild as it crosses
Highway 827 and proceeds west until it reaches Highways 63 and
656 where it ends. ==History==