Colorado constitution
Article IX
Section 10

(7) The board shall have the authority to undertake nonsimultaneous exchanges of land, by directing that the proceeds from a particular sale or other disposition be deposited into a separate account to be established by the state treasurer with the interest thereon to accrue to such account, and withdrawing therefrom an equal or lesser amount to be used as the purchase price for other land to be held and managed as provided in this article, provided that the purchase of lands to complete such an exchange shall be made within two years of the initial sale or disposition. Any proceeds, and the interest thereon, from a sale or other disposition which are not expended in completing the exchange shall be transferred by the state treasurer to the public school fund or such other trust fund maintained by the treasurer for the proceeds of the trust lands disposed of or sold. Moneys held in the separate account shall not be used for the operating expenses of the board or for expenses incident to the disposition or acquisition of lands.