Use of the OA&PS fell dramatically with the rapid stripping of most of the useful timber from the Algonquin area. Traffic was further reduced with the 1932 opening of the widened Welland Canal that allowed lakers to bypass trans-shipping points on Georgian Bay, along with the dramatic decrease in grain prices and trade during the Great Depression. The trestle bridge between Cache Lake and Lake of Two Rivers closed in 1933 due to safety concerns and was not re-built. Both ends of the now-separated line continued in use for some time; the western section between Parry Sound and Cache Lake ended services in 1952, while the eastern section saw use in some locations until 1959.