Sorry for the bump,
It seems that there is a siren at the Oliver Volunteer Fire Department, according to this article:
https://visitoliver.com/celebrating-100-years/
Apparently it sounds every Thursday evening. My friends who visited the town recently heard it go off.
Not sure exactly what manufacturer/model it is as I have been unable to see it on StreetView, but it sounded electromechanical in the video I saw it in. The video is not on YouTube, so unfortunately I cannot link it here. If anyone desperately wants to hear it, I will try to find a way to upload the video somewhere.