Idaho Spud Day has been a Shelley tradition since 1927, celebrating the potato crop and the farming families connected with it. The event is held on the third Saturday in September and turns an everyday Idaho staple into a full day of competitions, food and community traditions.
Visitors can watch or join activities such as the Spud Picking Contest, Spud Tug, potato sack races, French fry eating, baking contests and a parade. A pancake breakfast, fun run, vendors, car show and live entertainment broaden the schedule beyond potatoes. Shelley City Park serves as the main festival location, while some races and parade activities use other parts of town.