The proper name plural that’s really singular

I want to briefly revisit a singular/plural issue, especially as it relates to the use of possessives. I grew up in Grand Rapids, Michigan. The name Grand Rapids refers to the rapids on the Grand River, which flows through the city. So are the rapids plural? You bet they are. Does that make the name Grand Rapids a plural? Nope. Even though the name refers to a plural, the name itself is still just one name of one city. So when you’re using the name of the city in a possessive context, I know it looks funny, but it’s Grand Rapids’s streets, not Grand Rapids’ streets. The same is true for Cedar Rapids or Auburn Hills or Wuthering Heights. That city name that sounds plural (because its origin is plural) is actually a singular word, and has to be treated that way when you use it in a possessive context. 

This is why I moved to Royal Oak. It’s much less confusing here.