Who was Grover?

We've visited Grover Hotsprings many, many times now without giving too much thought into the name. This time, we started to think more about who Grover was. Well, who was he?
A sign above the springs tells a short history of the springs. Washoe Indian tribes visited the area for hundreds of years but Alvin Grover was the first man to establish a permanent settlement. He ran a dairy farm and developed the natural spring into a resort-type location, opening the Hotsprings Hotel in Markleeville town.
On this visit, we also learned about the Markleeville town cemetery on a hill above town. Most graves have lost their tombstones with only a half dozen remaining. One of those is the Grover family tombstone. One mystery has been solved, but another has surfaced: who is Samuel M. Grover? Local history books tell of Grover's daughter, Nellie, passing away at seven years old. The Grover tombstone has no mention of her, though. Instead, Samuel Grover's name is on the tombstone with a date and age of death identical to Nellie's. Were they twins? If so, why does Samuel go unmentioned in the history books? We'll get to the bottom of this.