The board may establish separate highway districts in counties containing more than three hundred thousand acres of unimproved unoccupied forest lands, for the purpose of constructing highways through such lands; such highway districts to be established upon the application of the owners of more than one-half to the non-resident lands therein. Any such highway district shall consist of contiguous tracts or parcels of land, and may include parts of one or more towns; and they may be changed, altered or abolished at any time by the board. Such board may appoint one or more commissioners to lay out and construct such highways in any such district, and prescribe the powers and duties, and direct the manner in which highway taxes shall be assessed, levied and collected upon the lands within the district, and the manner of expenditure thereof. If obligations should be issued on behalf of the district, the board may, for the purpose of repaying such loan, set aside and appropriate the highway taxes upon such lands, for a period not exceeding ten years from the time of making such loan. The board may, upon the application of the owners representing a majority in value, as shall be ascertained from the last annual assessment-roll of the real estate lying along the line of any highway, laid out through unimproved lands, in cases not provided for in the last preceding section, authorize the appropriation of the non-resident highway tax on the lands lying along such line, for the improvement of such highways. The board may direct the expenditure of any non-resident highway or bridge tax, set apart by an act of the legislature, in counties wherein such non-resident lands are situated, when the official life of commissioners appointed to receive and expend such taxes has expired.