For more detailed location descriptions (in lieu of driving directions), see the "Locations" section on the individual city pages. Note that those might not yet exist for all cities.
There are four different types of Sunshine Crops farms.
The achievementGrown in Idaho requires the player to complete five deliveries of potatoes from Sunshine Crops farms in Idaho. They are located in Grangeville, Nampa, Pocatello, and Twin Falls. For some reason, the progress is only counted if the player delivers the potatoes using any variants of the Dry Van trailers (i.e., Dry Van, Insulated Van, Refrigerated Van), and no progress will be made if the deliveries are completed by using the Grain Hopper trailer.