Number of wineries in Idaho. The number has increased more than five times since 2000. Among the 3 AVAs within the state, the Snake River Valley has the highest density of vineyards and wineries crafting mostly cabernet-based red wines from vineyards with volcanic soils. Starting this month, Alaska Airlines is offering an Idaho Wines Fly Free program. When you fly out of Boise or Lewiston, you’ll be able to check your first case of Idaho wines at no additional cost.