The DEW line has been partially gone for a while.[0] I do recall driving to visit my grandparents in northern Ontario in the 90s and we'd pass one of the old Pinetree Line radar stations. You could see it off on a hill from the highway. I think [1] was it and I think it's finally been cleaned up.

0. https://en.wikipedia.org /wiki/Distant_Early_Warning_Line#Deactivation_and_clean-up

1. https://en.wikipedia.org/wiki/CFS_Ramore