If a will created the life estate and specifies how the compensation will be distributed among the life tenants and owners of the remainder interests, those terms will establish the distribution. Otherwise:

(a) The owners of the remainder interests and the life tenant may enter into a right-of-way or other written agreement approved by the Secretary providing for the distribution of rent monies under the right-of-way; or

(b) If the owners of the remainder interests and life tenant did not enter into an agreement for distribution, the life tenant will receive payment in accordance with the distribution and calculation scheme set forth in part 179 of this chapter.