The identification number sign shall be, no less than four feet nor more than six feet above the ground on a substantial, maintained support structure. The view of the identification numbers from the water must be unobstructed and maintained. All primary letters, numbers, and symbols shall be a minimum of 3 1/2 inches in height, with a one-half inch stroke, and shall contrast with the background color. Contact Community Development at 208-446-1070 for more information.