There is another cover that is flush with the ground about 50 feet or so away. It looks similar to this one, but like I said, the cover itself doesn't rise out of the ground. There is also a sewer cover in the yard (it is labeled). I think the house was built in the mid 40's. I don't know if that is pertinent info or not. Most everyone around here is connected to town sewerage. Anyway, thanks for the possibilities.

Rboert, I did not pull the cover. Thankfully, I am not supposed to