Idaho Code § 39-107C
The director of the department of environmental quality may receive on behalf of the department any moneys or real or personal property donated, bequeathed, devised or conditionally granted to the department. Moneys received directly or derived from the sale of such property shall be held in a trust known as the environmental protection trust, which is hereby established, reserved, set aside, appropriated and made available until expended and used and administered to carry out the terms and conditions of such donation, bequest, devise or grant and to pay the costs and expenses arising from investment of the trust. There is hereby created in the state treasury a fund to be known as the "environmental protection trust fund," which shall consist of moneys held in the environmental protection trust. Pending expenditure or use, surplus moneys in the environmental protection trust shall either be invested by the state treasurer in the manner provided for idle state moneys in the state treasury by section 67-1210, Idaho Code, or, in the alternative and with the concurrence of the director of the department, the state treasurer, and the endowment fund investment board, be invested with the endowment fund investment board pursuant to chapter 7, title 57, Idaho Code. Interest received on all such investments shall be paid into the environmental protection trust.
Idaho Code § 39-107C