You have to be from Idaho to call yourself an Idahoan. That same rings true for potatoes. The term "Idaho potato" gets thrown around a lot in cooking conversations, usually when referring to Russet potatoes. Sometimes the potatoes are Russet, sometimes they're Idaho; sometimes they are both and sometimes they are neither. It all comes down to what variety of potato you're working with and where it was grown.
The distinction between Idaho and Russet potatoes is this: Idaho potatoes must be grown in Idaho. The label refers only to where the potatoes were grown and harvested, not any specific variety. For example, as long as the potato was grown in Idaho, it doesn't matter if it's Russet, Red Thumb fingerling, Yukon gold or Yellow Finn. Even those bright purple Terra Rosa potatoes can be Idaho if that's where they were born and grown.
Russet potatoes are those most typically misidentified as Idaho. In fact, the two terms are often used interchangeably. This is perhaps because Russet potatoes are the most popular and well known, according to the Idaho Potato Commission. Calling Russet potatoes "Idaho potatoes" not only ignores the potato's origin, it also ignores the subtle differences among Russet varieties.
Russet potatoes are the stereotypical, brown-skinned workhorse potatoes that are usually heavily stocked at grocery stores. They're best when prepared as baked potatoes, mashed potatoes and fried potatoes because of their low moisture and high starch content. They're not the best fit for dishes such as potato salad and soups. Waxy, low-starch potatoes, such as Russian Banana or Rose Finn Apple, hold their shape better in these types of dishes.
Idaho produces several varieties of Russet potatoes, such as the classic Premiere Russet, Western Russet, Umatilla Russet, Classic Russet and Ranger Russet. Even though Idaho produces a lot of Russets, they also put the Idaho name on red, golden and blue varieties with low, medium or high starch contents. You can find a true Idaho potato to match any dish.