The community began to decline during the 20th century as pioneer industries became increasingly obsolete. When Ontario Highway 16 was constructed around 1918, more traffic came through the community. This led to the construction of a small general store and gas pumps, possibly the last businesses to be established in Glen Smail. By the 1950s, small family farms began to be less profitable due to improved infrastructure and few remained operational in the village. In the 1970s, the land was sold off to the Land Bank and many structures were subsequently demolished. As of 2016, the community consists of sparse residential properties with no businesses in operation.