The first settlers in Granby realized the sunny days and cool nights were perfect for growing one crop in particular, lettuce. Lettuce farming boomed in the 1920's and a new industry was born. Granby had become an important railway center as tracks were laid over the Divide at Rollins Pass,giving the Moffat Railroad access to Salt Lake City.
Granby produced some of the best-known lettuce in America. There are even tales that New York's Waldorf-Astoria Hotel bragged of their “Granby Lettuce” on the menu. Then a blight settled into the soil, probably brought in by the wooden crates used for shipping, and the lettuce business was ruined. Since then, ranching has replaced agriculture as Granby's major industry.