Daniel B. Martin wrote:
I first thought it was a really strange bird house ...

It might be a bat box.

Could be. I googled for bat and bee houses and found nothing like it. The
bat houses all had either horizontal slots or open bottoms, the bee houses
were all for solitary bees (just holes drilled in wood), butterfly houses
had vertical slots. I asked at the boat house (at Bond Lake) and no one
knew what I was talking about, but ~someone~ put it there. There was a
little ledge for landing and and those dowels going all the way through (as
far as I could tell from 15' anyway). And lots of bees!

Beth