An important update; The mystery pipe conclusion.

 I'm not sure if I mentioned it here, but last week I started trying to dig up this weird pipe sticking out of the lawn out near the road. I thought it was a sheared off old metal pipe fence post. I dug and dug, until I hit a collar. Then I stopped and called DigSafe. This was no left-over mailbox post.

DigSafe determined that it wasn't gas or electric, so I could go to town digging as far as they were concerned. But I wasn't convinced. That sucker wasn't budging for anything. I called the town water department. The lady on the other end wasn't convinced it was their problem either, but said she's talk to some folks and get back to me. She did, later that day, leaving me a message telling me that it was a "stub".
When the water company ran a main down the road a number of years back, they put little stubs in so that properties could tie in later without needing to dig up the roadbed. That's cool, but now *I* wasn't convinced. This (above) didn't exactly look like an intentional arrangement.

The water lady went on vacation. I waited for her to get back and called in again. I wanted a set of real live eyeballs to look at this. She wasn't pleased that I was wasting her time, but she finally relented to send someone up. A little while later, a man in a big town pickup truck pulled up. "Yup," he said, "it's a stub. But it's seen a snowplow or two."
He went on to explain the long wrenches that would be fished down the pipe to turn the water on and off to the street. (Mine is pretty shallow.)
He also told me that should I ever want to tie into the main, they would definitely have to replace this part anyway (up to this point is their responsibility), so he could just cut it off. He left to get his saw, and about an hour later he came back, marked the street, and cut it off for me.

Thanks Water Guy!

Now all I have to do is take measurements (just in case) and back fill it.
One less thing to bounce my poor lawnmower off of!