This is a Wide-Vision, Centre-Cupola Caboose, made of steel, meaning it was probably in service until the demise of cabooses in the last century. It is Displayed beside the former CP Station, now the Claresholm & District Museum and Visitor Information Centre.
Apparently it was built at the CP Rail Angus Shop in Montreal in December of 1972. Its designation could have been changed to 439924 in 1995, but we wouldn't swear to it. OR perhaps it was first 439924 and changed to 434426. Getting mixed signals. Beyond that we know nothing of this caboose.
In any event here's an informative PDF on extant old
Railway Cars in Alberta, Saskatchewan and Manitoba.