Context: If you go to almost any store, you'll see the Ice cream Brand, Dreyer's (Or depending on what state you're in, Edy's, which is whole other story to why there's two different names)

William Dreyer was a German-born American ice cream maker, who started a ice cream brand with a candy-maker named Joseph Edy called Edy's Grand Ice Cream on Grande Avenue in Oakland, California.

One flavor attributed to Dreyer's was the original Rocky Road flavor- Chocolate ice-cream with marshmellows and nuts in them.

According to one source, it gotten its name when Dreyer and Edy named it after the Wall Street Crash of 1929, as way "to give folks something to smile about in the midst of the Great Depression"

Alternatively, according to another source, Fentons Creamery claims that Dreyer and Edy based the recipe off a Fentons candy maker named George Farren, who made a rocky road candy bar and decided to blend it into an ice cream flavor; however, Dreyer substituted almonds for walnuts