It does - but not overly surprising when you consider that many coop lines are well past a half-century old now.

I wonder if the co-op will simply just bury the feeder in the years to come. Seems like a popular thing they're doing now here-the 7200V line near my property (some poles even had the REA tags on them) has now been chopped up into 'islands' of overhead portions over the last few years. I'm pretty much expecting them to just underground the rest in the next 5-10 years.

Berkeley Power Coop where I live has been recently burying lines quite extensively- even in rural areas. I did not know other co-ops have also been doing the same thing.

I can think of a few that have been burying the main trunk lines and leaving the branch lines overhead - Southeastern (SD), Whetstone Valley (SD), Wild Rice (MN), Verendrye (ND).

On the other hand, three coops I know of in SD are all in arid areas and all run 24.9kV due to the LONG distances involved due to ranch operations - and all three are primarily overhead construction. One of those 3 (West Central) actually has a bunch of 2400V delta in the towns they serve!