No municipal corporation may be formed unless:
(1) (a) the number of inhabitants is 300 or upwards; or
(b) the community was a townsite owned and built by the U.S. government prior to April 3, 1981; and
(2) the boundary of the proposed territory to be incorporated is more than 3 miles from the boundary, measured from the nearest point between the two, of any presently incorporated city or town or there is presented to the board appropriate evidence that any presently incorporated city or town within 3 miles which legally could annex has refused to annex the proposed territory.